1 % (c) 2009-2025 Lehrstuhl fuer Softwaretechnik und Programmiersprachen,
2 % Heinrich Heine Universitaet Duesseldorf
3 % This software is licenced under EPL 1.0 (http://www.eclipse.org/org/documents/epl-v10.html
4
5 :- module(b_ast_cleanup, [clean_up/3, clean_up_pred/3,
6 clean_up_pred_or_expr/3,
7 clean_up_pred_or_expr_with_path/4, % provide initial path, used for eventb context infos
8 clean_up_l_wo_optimizations/4,
9 clean_up_l_with_optimizations/4,
10 check_used_ids_info/4, recompute_used_ids_info/2,
11 definitely_not_empty_and_finite/1, definitely_infinite/1, % TO DO: move to another module
12 get_unique_id/2,
13 predicate_level_optimizations/2,
14 perform_do_not_enumerate_analysis/5,
15 has_top_level_wd_condition/1]).
16
17 :- use_module(module_information,[module_info/2]).
18 :- module_info(group,typechecker).
19 :- module_info(description,'This module implements transformations/simplifications on the AST.').
20
21 :- set_prolog_flag(double_quotes, codes). % relevant for detecting prob-ignore, test 2151 on SWI
22
23 :- use_module(tools, [safe_atom_chars/3,exact_member/2,foldl/4,filter/4]).
24 :- use_module(tools_lists, [length_less/2]).
25 :- use_module(error_manager).
26 :- use_module(debug).
27 :- use_module(self_check).
28 :- use_module(bsyntaxtree).
29 :- use_module(translate,[print_bexpr/1, translate_span/2, get_definition_context_from_span/2]).
30 :- use_module(btypechecker, [unify_types_strict/2]).
31 :- use_module(preferences,[get_preference/2]).
32 :- use_module(custom_explicit_sets,[convert_to_avl/2]).
33 :- use_module(prob_rewrite_rules(b_ast_cleanup_rewrite_rules),[rewrite_rule_with_rename/7]).
34 :- use_module(b_enumeration_order_analysis, [find_do_not_enumerate_variables/4]).
35 :- use_module(performance_messages,[perfmessage/2]).
36 :- use_module(b_operation_guards,[get_operation_propositional_guards/6]).
37
38 :- use_module(library(lists)).
39 :- use_module(library(ordsets)).
40 :- use_module(library(system), [environ/2]).
41
42 % entry point for cleaning up predicates; ensures that global, predicate-level optimizations also applied
43 clean_up_pred(Expr,NonGroundExceptions,CleanedUpExpr) :-
44 ? clean_up(Expr,NonGroundExceptions,CExpr),
45 (get_texpr_type(CExpr,pred)
46 -> predicate_level_optimizations(CExpr,CleanedUpExpr)
47 ; add_internal_error('Not predicate: ',clean_up_pred(Expr,NonGroundExceptions,CleanedUpExpr)),
48 CleanedUpExpr = CExpr).
49
50 % Warning: arguments swapped with clean_up for maplist !
51 clean_up_pred_or_expr(NonGroundExceptions,Expr,CleanedUpExpr) :-
52 ? clean_up_pred_or_expr_with_path(NonGroundExceptions,Expr,CleanedUpExpr,[]).
53 clean_up_pred_or_expr_with_path(NonGroundExceptions,Expr,CleanedUpExpr,Path) :-
54 clean_up_init(NonGroundExceptions,Expr,Expr1),
55 ? clean_up_aux(Expr1,NonGroundExceptions,CExpr,Path),
56 (get_texpr_type(CExpr,pred)
57 -> predicate_level_optimizations(CExpr,CleanedUpExpr,Path)
58 ; CleanedUpExpr = CExpr).
59
60 %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
61
62 % clean up some code afterwards
63 clean_up(Expr,NonGroundExceptions,CExpr) :- % clean-up with init
64 clean_up_init(NonGroundExceptions,Expr,Expr1),
65 ? clean_up_aux(Expr1,NonGroundExceptions,CExpr,[]).
66 clean_up_aux(Expr1,NonGroundExceptions,CExpr,Path) :- % performs no init
67 (preferences:get_preference(normalize_ast,true)
68 -> cleanups(normalize,Expr1,[],Expr2,Path)
69 ; Expr2=Expr1),
70 cleanups(pre,Expr2,[],TPExpr,Path),
71 remove_bt(TPExpr,PExpr,LExpr,TLExpr),
72 ? syntaxtransformation(PExpr,Subs,_,NewSubs,LExpr),
73 functor(PExpr,F,N),
74 % recursively clean up sub-expressions
75 ? clean_up_l(Subs,NonGroundExceptions,NewSubs,F/N,1,Path),
76 cleanups(post,TLExpr,[],CExpr,Path).
77 %, tools_printing:print_term_summary(cleaned_up(CExpr)),nl.
78
79 % just run post-phase
80 %cleanups_post(Expr,CleanedupExpr) :- cleanups(post,Expr,[],CleanedupExpr,[]).
81
82 clean_up_init(NonGroundExceptions,Expr,Expr2) :-
83 % ensure that WD info is available also for pre phase
84 % also pre-transform large set_extensions; they are only later transformed using eval_set_extension
85 ? (transform_bexpr_td_with_scoping(b_ast_cleanup:try_evaluate_set_extension,Expr,Expr1),
86 ? transform_bexpr(b_ast_cleanup:compute_wd_info_and_norm_record_types(NonGroundExceptions),Expr1,Expr2) -> true
87 ; add_internal_error('Call failed:',clean_up_init(NonGroundExceptions,Expr,_)), Expr2=Expr).
88
89
90 :- use_module(kernel_records,[normalise_record_types/4]).
91 :- use_module(bsyntaxtree,[transform_bexpr/3]).
92 compute_wd_info_and_norm_record_types(NonGroundExceptions,b(E,Type0,I),b(E,Type2,NInfo)) :-
93 ? (member(contains_wd_condition,I) -> NInfo=I
94 ? ; is_possibly_undefined(E)
95 -> NInfo = [contains_wd_condition|I]
96 ; NInfo = I
97 ),
98 (NonGroundExceptions = do_not_ground_types -> Type2=Type0
99 ; ground_type_to_any(Type0,NonGroundExceptions),
100 normalise_record_types(Type0,NonGroundExceptions,Type1,HasRecords),
101 % difference between Type1/0 in test 1906
102 (HasRecords == true,Type1 \= Type0 -> Type2=Type1 ; Type2=Type0)
103 ).
104
105 try_evaluate_set_extension(set_extension(List),Res,LocalIds) :-
106 (extension_should_be_evaluated(List),
107 evaluate_set_extension(List,EvaluatedList,LocalIds),
108 convert_to_avl(EvaluatedList,AVL)
109 % evaluate simple explicit set extensions: avoid storing & traversing position info & AST
110 -> (debug_mode(on) -> format('EVAL SET EXTENSION: ',[]), translate:print_bvalue(AVL),nl ; true),
111 Res=value(AVL)
112 ;
113 Res=set_extension(List) % avoid traversing inside set_extension, can be very large
114 ).
115 try_evaluate_set_extension(set_extension(List),Res,LocalIds) :-
116 (extension_should_be_evaluated(List),
117 evaluate_seq_extension_to_avl(List,AVL,LocalIds)
118 -> (debug_mode(on) -> format('EVAL SEQUENCE EXTENSION: ',[]), translate:print_bvalue(AVL),nl ; true),
119 Res=value(AVL)
120 ; Res=sequence_extension(List) % avoid traversing inside set_extension, can be very large
121 ).
122
123
124 :- use_module(library(ordsets),[ord_nonmember/2, ord_add_element/3]).
125 % apply the clean-up rules to an expression until all
126 % applicable rules are processed
127 % cleanups(Phase,Expr,AppliedRules,Result,Path):
128 % Phase: pre or post or normalize
129 % Expr: the expression to clean up
130 % AppliedRules: a sorted list of clean up rules that have been already applied
131 % and must only be apply once ("single" mode)
132 % Result: the cleaned-up expression
133 % Path: list of outer functors leading to this expression; can be used to decide about applicability of rules
134 cleanups(Phase,Expr,AppliedRules,Result,Path) :-
135 %% print(cleanups(Phase,Expr,AppliedRules,Result,Path)),nl,
136 % set up co-routines that ensure that "Rule" is not applied if
137 % is in the list AppliedRules
138 start_profile_rule(RuleInfos),
139 assure_single_rules(AppliedRules,Mode,Rule),
140 ? ( cleanup_phase(Phase,Expr,NExpr,Mode/Rule,Path) -> % try to apply a rule (matching the current phase)
141 ( Mode==single -> ord_add_element(AppliedRules,Rule,AppRules) % if the rule is marked as "single", we add to the list of already applied rules
142 ; Mode==multi -> AppRules = AppliedRules % if "multi", we do not add it to the list, the rule might be applied more than once
143 ; add_error_fail(b_ast_cleanup,'Unexpected rule mode ',Mode)
144 ),
145 stop_profile_rule(Rule,Mode,Phase,Expr,NExpr,RuleInfos),
146 %(NExpr=b(_,_,I),bsyntaxtree:check_infos(I,Rule) -> true ; true),
147 cleanups(Phase,NExpr,AppRules,Result,Path) % continue recursively with the new expression
148 ; % if no rule matches anymore,
149 Result = Expr, % we leave the expression unmodified
150 Mode=multi, Rule=none). % and unblock the co-routine (see assure_single_rules/3)
151
152
153 :- if(environ(prob_safe_mode,true)).
154 start_profile_rule([R1,W1]) :- statistics(runtime,[R1,_]),statistics(walltime,[W1,_]).
155 stop_profile_rule(Rule,Mode,Phase,Expr,_NExpr,[R1,W1]) :-
156 statistics(runtime,[R2,_]),statistics(walltime,[W2,_]), DeltaW is W2-W1, DeltaR is R2-R1,
157 (DeltaW < 20 -> true ; format('Firing AST cleanup rule ~w (mode:~w) in phase ~w took ~w ms (~w ms walltime)~n',[Rule,Mode,Phase,DeltaR,DeltaW]), translate:print_span(Expr),nl),
158 runtime_profiler:register_profiler_runtime(Rule,ast_cleanup,unknown,DeltaR,DeltaW).
159 % print(fired_rule(Rule,Mode,Phase)),nl, translate:print_bexpr_or_subst(Expr), print(' ===> '),nl, translate:print_bexpr_or_subst(NExpr),nl, print_ast(_NExpr),nl. %% COMMENT IN TO SEE applied RULES <---------------
160 %(map_over_typed_bexpr(b_ast_cleanup:check_valid_result,NExpr) -> true ; true), % comment in to check output after every firing of a rule
161 :- else.
162 start_profile_rule(_).
163 stop_profile_rule(_,_,_,_,_,_).
164 :- endif.
165
166 %check_valid_result(b(xexists([b(identifier(msgXX),integer,_)|_],_),pred,Infos)) :- nonmember(allow_to_lift_exists,Infos),print(missing_info),nl,trace,fail.
167
168 assure_single_rules([],_Mode,_Rule) :- !.
169 assure_single_rules(AppliedRules,Mode,Rule) :-
170 assure_single_rules2(AppliedRules,Mode,Rule).
171 :- block assure_single_rules2(?,-,?),assure_single_rules2(?,?,-).
172 assure_single_rules2(_AppliedRules,_,none) :- !.
173 assure_single_rules2(_AppliedRules,multi,_) :- !.
174 assure_single_rules2(AppliedRules,_,Rule) :-
175 % typically AppliedRules not very long; would also do: \+ member(Rule, AppliedRules).
176 ord_nonmember(Rule,AppliedRules).
177
178 cleanup_phase(Phase,OTExpr,NTExpr,Mode/Rule,Path) :-
179 create_texpr(OExpr,OType,OInfo,OTExpr),
180 check_generated_info(OInfo,entry,Path),
181 create_texpr(NExpr,NType,NInfo,NTExpr),
182 ? cleanup_phase2(Phase,OExpr,OType,OInfo,NExpr,NType,NInfo,Mode/Rule,Path),
183 check_generated_info(NInfo,Rule,Path).
184 cleanup_phase2(normalize,OExpr,OType,OInfo,NExpr,NType,NInfo,Mode/Rule,_Path) :-
185 decompose_rule(Mode_Rule,Mode,Rule),
186 cleanup_normalize(OExpr,OType,OInfo,NExpr,NType,NInfo,Mode_Rule),
187 (debug_mode(off) -> true
188 ; print('Rewritten: '), print_bexpr(b(OExpr,OType,OInfo)),nl,
189 print(' Into: '), print_bexpr(b(NExpr,NType,NInfo)),nl
190 ).
191 cleanup_phase2(pre,OExpr,OType,OInfo,NExpr,NType,NInfo,Mode/Rule,Path) :-
192 decompose_rule(Mode_Rule,Mode,Rule),
193 ? cleanup_pre_with_path(OExpr,OType,OInfo,NExpr,NType,NInfo,Mode_Rule,Path).
194 cleanup_phase2(post,OExpr,OType,OInfo,NExpr,NType,NInfo,Mode/Rule,Path) :-
195 decompose_rule(Mode_Rule,Mode,Rule),
196 ? cleanup_post_with_path(OExpr,OType,OInfo,NExpr,NType,NInfo,Mode_Rule,Path).
197 % check_ast(b(NExpr,NType,NInfo)),nl.
198
199 :- block decompose_rule(-,?,?).
200 decompose_rule(Mode_Rule,Mode,Rule) :-
201 (functor(Mode_Rule,'/',2)
202 -> Mode_Rule = Mode/Rule
203 ; add_internal_error('Illegal cleanup rule, missing mode: ',Mode_Rule),fail).
204
205 check_generated_info(Info,Rule,Path) :-
206 get_preference(prob_safe_mode,true),
207 (select(used_ids(_),Info,I1) -> member(used_ids(_),I1)),!,
208 format('Illegal used ids generated by ~w within ~w~n Infos=~w~n',[Rule,Path,Info]),
209 add_internal_error('Illegal Info generated by rule: ',Rule),
210 fail.
211 check_generated_info(_,_,_).
212
213 clean_up_l_wo_optimizations(Rest,NonGroundExceptions,CRest,SectionName) :-
214 maplist(clean_up_init(NonGroundExceptions),Rest,Rest1),
215 clean_up_l(Rest1,NonGroundExceptions,CRest,top_level(SectionName),1,[]).
216 clean_up_l([],_,[],_Functor,_Nr,_Path).
217 clean_up_l([Expr|Rest],NonGroundExceptions,[CExpr|CRest],Functor,ArgNr,Path) :-
218 ? clean_up_aux(Expr,NonGroundExceptions,CExpr,[path_arg(Functor,ArgNr)|Path]),
219 A1 is ArgNr+1,
220 ? clean_up_l(Rest,NonGroundExceptions,CRest,Functor,A1,Path).
221
222
223 % MAIN ENTRY POINT for b_machine_construction, bmachine_eventb, proz
224 % same as clean_up_l but also applies predicate_level_optimizations
225 % Context is just the name of the section/context in which the optimizations are run
226 clean_up_l_with_optimizations(Rest,NonGroundExceptions,CRest,Context) :-
227 %clean_up_l(Rest,NonGroundExceptions,CRest,top_level,1,[]).
228 ? (clean_up_l_with_opt(Rest,NonGroundExceptions,CleanedUpRest,top_level(Context),1,[]) -> CRest=CleanedUpRest
229 ; add_internal_error('Call failed:',clean_up_l_with_optimizations(Rest,NonGroundExceptions,CRest,Context)),
230 CRest=Rest
231 ).
232 clean_up_l_with_opt([],_,[],_Functor,_Nr,_Path).
233 clean_up_l_with_opt([Expr|Rest],NonGroundExceptions,[CExpr|CRest],Functor,ArgNr,Path) :-
234 %print('Cleaning up: '),translate:print_bexpr_or_subst(Expr),nl,
235 clean_up_init(NonGroundExceptions,Expr,Expr1),
236 ? clean_up_pred_or_expr_with_path(NonGroundExceptions,Expr1,CExpr,[path_arg(Functor,ArgNr)|Path]),
237 A1 is ArgNr+1,
238 ? clean_up_l_with_opt(Rest,NonGroundExceptions,CRest,Functor,A1,Path).
239
240 :- use_module(specfile,[animation_mode/1, animation_minor_mode/1]).
241 % cleanup_pre(OldExpr,OldType,OldInfo,NewExpr,NewType,NewInfo,Mode/Rule)
242
243 % optional normalization rules
244 % These rules are now generated using the prob_rule_compiler
245 %cleanup_normalize(empty_sequence,Type,Info,empty_set,Type,Info, multi/apply_normalization_rule(empty_sequence)). % rule probably not useful as empty_sequence converted to value([])?
246 cleanup_normalize(Expr,Type,Info,NewExpr,NewType,NewInfo, multi/apply_normalization_rule(Rule)) :-
247 b_ast_cleanup_rewrite_rules:normalization_rule_with_rename(Expr,Type,Info,NewExpr,NewType,NewInfo,Rule),
248 (debug_mode(off) -> true
249 ; format('Use rewrite_rule_normalize ~w~n',[Rule]),
250 print_bexpr(b(NewExpr,NewType,NewInfo)),nl
251 ),
252 (ground(NewExpr) -> true
253 ; print(not_ground_rewrite(Rule,Type,Info)),nl,
254 write(Expr),nl, write(' --> '),nl, write(NewExpr),nl,
255 fail).
256
257 never_transform_or_optimise(boolean_false).
258 never_transform_or_optimise(boolean_true).
259 %never_transform_or_optimise(bool_set).
260 never_transform_or_optimise(empty_set).
261 never_transform_or_optimise(empty_sequence). % except for normalization (cf above)
262 never_transform_or_optimise(falsity).
263 %never_transform_or_optimise(max_int).
264 %never_transform_or_optimise(min_int).
265 never_transform_or_optimise(truth).
266 never_transform_or_optimise(identifier(_)).
267 never_transform_or_optimise(integer(_)).
268 never_transform_or_optimise(real(_)).
269 never_transform_or_optimise(string(_)).
270 never_transform_or_optimise(value(_)) :- preferences:preference(normalize_ast, false).
271
272
273 % first check for a few expressions that never need to be optimised, rewritten:
274 cleanup_pre_with_path(E,_,_,_,_,_,_,_) :- never_transform_or_optimise(E),!,fail.
275 % TO DO: think about enabling the following clause
276 cleanup_pre_with_path(exists(AllIds,P),pred,I,exists(AllIds,P),pred,NewI,single/annotate_toplevel_exists,Path) :-
277 % mark the exists inside {paras| #(AllIds).(P)} as allowed to be lifted; relevant for test 1945 (although delayed semi_lifting in b_test_exists_wo_expansion also solves performance issue)
278 Path = [H|_], % TODO: also deal with lambda and other quantifications
279 H=path_arg(comprehension_set/2,1),
280 % % TO DO: add some conditions under which we allow to lift
281 get_preference(data_validation_mode,true), % TODO: check if we cannot enable this more generally
282 (debug_mode(off) -> true ; add_message(b_ast_cleanup,'Marking exists for lifting: ',AllIds,I)),
283 add_info_if_new(I,allow_to_lift_exists,NewI).
284 % mark existential quantifier as outermost: no need to delay it in b_interpreter:b_test_exists_wo_expansion
285 cleanup_pre_with_path(OExpr,OType,OInfo,NExpr,NType,NInfo,Mode_Rule,_) :-
286 ? cleanup_pre(OExpr,OType,OInfo,NExpr,NType,NInfo,Mode_Rule).
287
288 % Now cleanup_pre rules that do not require path:
289
290 cleanup_pre(block(TS),subst,_,Subst,subst,Info,multi/remove_block) :-
291 !,get_texpr_expr(TS,Subst),get_texpr_info(TS,Info).
292 % replace finite by truth
293 cleanup_pre(finite(S),pred,I,truth,pred,[was(finite(S))|I],multi/remove_finite) :-
294 % preferences:get_preference(disprover_mode,false), % keep finite in disprover goals
295 get_texpr_type(S,Type),
296 (typing_tools:is_provably_finite_type(Type) -> true
297 % ; is_infinite_ground_type(Type) -> fail
298 % ; print(no_longer_assuming_finite(Type)),nl,b_global_sets:portray_global_sets,nl,fail
299 ),!. % add_message(ast,'Removed : ',b(finite(S),pred,I),I).
300 /*
301 cleanup_pre(domain(SETC),Type,I,
302 comprehension_set(DomainIds,NewPred),Type,I,multi/dom_let_pred) :-
303 get_texpr_expr(SETC,comprehension_set(CompIds,CompPred)),
304 get_domain_range_ids(CompIds,DomainIds,[RangeId]),
305 get_texpr_ids(CompIds,UnsortedIds), sort(UnsortedIds,Blacklist),
306 conjunction_to_list(CompPred,Preds),
307 select_equality(TId,Preds,Blacklist,Expr,Rest,_UsedIds,check_well_definedness),
308 same_id(TId,RangeId,_),
309 !,
310 LetIds = [RangeId], Exprs = [Expr],
311 conjunct_predicates(Rest,RestPred),
312 NewPred = b(let_predicate(LetIds,Exprs,RestPred),pred,[generated(domain)]),
313 print('Translated dom({...,x|x=E&...}) into: '),
314 print_bexpr(b(comprehension_set(DomainIds,NewPred),Type,[])),nl.
315 */
316 /* strangely enough: this does not seem to buy anything:
317 cleanup_pre(domain(SETC),Type,I,
318 let_expression(LetIds,Exprs,NewExpr),Type,[generated(domain)|I],multi/dom_let_expr) :-
319 get_texpr_expr(SETC,comprehension_set(CompIds,CompPred)),
320 get_domain_range_ids(CompIds,DomainIds,[RangeId]),
321 get_texpr_ids(CompIds,UnsortedIds), sort(UnsortedIds,Blacklist),
322 conjunction_to_list(CompPred,Preds),
323 select_equality(TId,Preds,Blacklist,Expr,Rest,_UsedIds,check_well_definedness),
324 same_id(TId,RangeId,_),
325 !,
326 LetIds = [RangeId], Exprs = [Expr],
327 conjunct_predicates(Rest,RestPred),
328 get_texpr_info(SETC,CInfo),
329 NewExpr = b(comprehension_set(DomainIds,RestPred),Type,CInfo),
330 print('Translated dom({...,x|x=E&...}) into: '), print_bexpr(b(let_expression(LetIds,Exprs,NewExpr),Type,[])),nl.
331 */
332 % exchange quantified union by generalized union
333 cleanup_pre(QUANT,Type,I,
334 let_expression(LetIds,Exprs,NewExpr),Type,[generated(QuantOP)|I],multi/quant_union_inter_let) :-
335 get_preference(optimize_ast,true),
336 quantified_set_operator(QUANT,QuantOP,AllIds,Pred,Expr),
337 conjunction_to_nontyping_list(Pred,Preds),
338 % The ids are needed to build a "black list"
339 get_sorted_ids(AllIds,Ids),
340 find_one_point_rules(AllIds,Preds,Ids,LetIds,Exprs,RestIds,NewPreds),
341 % only succeed if we found at least one id which can be rewritten as let
342 LetIds = [_ID1|_],
343 !,
344 (RestIds=[],NewPreds=[] -> NewExpr=Expr
345 % UNION(x).(x=E|Expr) --> LET x BE x=E in Expr END
346 ; RestIds = [] -> conjunct_predicates_with_pos_info(NewPreds,NewPred),
347 % UNION(x).(x=E & NewPred|Expr) --> LET x BE x=E in IF NewPRED THEN Expr ELSE {} END END
348 NewExpr = b(if_then_else(NewPred,Expr,b(empty_set,Type,[])),Type,I)
349 ; conjunct_predicates_with_pos_info(NewPreds,NewPred),
350 ? quantified_set_operator(NewQUANT,QuantOP,RestIds,NewPred,Expr),
351 NewExpr = b(NewQUANT,Type,I)
352 ),
353 (debug_mode(off) -> true
354 ; print('Translated UNION/INTER into: '), print_bexpr(b(let_expression(LetIds,Exprs,NewExpr),Type,[])),nl).
355 cleanup_pre(quantified_union(Ids,Pred,Expr),Type,I,DomCOMPSET,Type,I,multi/quant_union_into_comprehension) :-
356 singleton_set_extension(Expr,CoupleExpr),
357 nested_couple_to_list(CoupleExpr,List), % we have UNION(..).(...| { A |-> B }) --> List = [A,B]
358 match_ids(List,Ids,AllIds,RestIds),
359 (RestIds = []
360 -> true % UNION(x,y).(x:INTEGER & y=x+1|{x|->y}) --> {x,y| x:INTEGER & y=x+1} = %x.(...).
361 ; % UNION(y,x,z).(x:INTEGER & y=x+1|{x|->y}) --> dom({x,y,z| x:INTEGER & y=x+1})
362 % used to fail test 1101; check on List relevant for test 2359
363 List = [_,_|_] % at least two ids, otherwise use quant_union translation below: ran( %(Ids).(Pred|One) )
364 ),
365 COMPSET = comprehension_set(AllIds,Pred),
366 generate_dom_for_ids(RestIds,COMPSET,Type,I,TDomCOMPSET), % add one dom(.) construct per ID that is projected away
367 (debug_mode(off) -> true
368 ; print('Translated UNION over identifier couples into: '), print_bexpr(TDomCOMPSET),nl),
369 % check_ast(TDomCOMPSET), will complain about redundant typing as we are still in pre phase
370 TDomCOMPSET = b(DomCOMPSET,Type,_).
371 cleanup_pre(quantified_union(Ids,Pred,Expr),Type,I,Res,Type,[was(quantified_union)|I],multi/quant_union_symbolic) :-
372 memberchk(prob_annotation('SYMBOLIC'),I),
373 % UNION(Ids).(Pred|Expr) --> {u| #Ids.(Pred & u:Expr)}
374 get_texpr_set_type(Expr,IdType),
375 !,
376 get_unique_id_inside('__UNION__',Pred,Expr,FRESHID),
377 NewTID = b(identifier(FRESHID),IdType,[]),
378 safe_create_texpr(member(NewTID,Expr),pred,Member),
379 create_exists_opt(Ids,[Pred,Member],Exists),
380 Res = comprehension_set([NewTID],Exists),
381 (debug_mode(off) -> true ; print('UNION @symbolic: '), print_bexpr(b(Res,Type,I)),nl).
382 % exchange quantified union by generalized union
383 cleanup_pre(quantified_union(Ids,Pred,Expr),Type,I,Res,Type,I,multi/quant_union) :-
384 !,
385 ((get_preference(convert_comprehension_sets_into_closures,false), % for test 1101: UNION is a form of let and forces computation at the moment; translating it into a construct without union means that it may be kept symbolic
386 singleton_set_extension(Expr,One) %, debug:bisect(Expr,[1,1,1,1,1,1,1])) % [1,1,1,1,1,1,1] slow; 1,1,0 1,1,1,0 fast
387 )
388 % UNION(Ids).(Pred|{One}) --> ran( %(Ids).(Pred|One) )
389 -> quantified_set_op(Ids,Pred,One,quantified_union,I,TRes),
390 get_texpr_expr(TRes,Res),
391 (debug_mode(off) -> true ; print('UNION - SINGLETON: '), print_bexpr(TRes),nl)
392 ;
393 % UNION(Ids).(Pred|Expr) --> union( ran( %(Ids).(Pred|Expr) ) )
394 quantified_set_op(Ids,Pred,Expr,quantified_union,I,Set),
395 Res = general_union(Set)
396 ).
397 %alternate encoding:
398 %cleanup_pre(quantified_union(Ids,Pred,Expr),Type,I,Set,Type,I,multi/quant_union) :-
399 %poses problem to test 614, 1101
400 % !,quantified_union_op(Ids,Pred,Expr,Type,Set).
401 % exchange quantified intersection by generalized intersection
402 cleanup_pre(quantified_intersection(Ids,Pred,Expr),Type,I,general_intersection(Set),Type,I,multi/quant_inter) :-
403 !,quantified_set_op(Ids,Pred,Expr,quantified_intersection,I,Set).
404 cleanup_pre(function(FUN,Argument),Type,I,Result,Type,I2,RULE) :-
405 ? cleanup_pre_function(FUN,Argument,Type,I,Result,I2,RULE).
406 cleanup_pre(first_projection(A,B),Type,I,Set,Type,[was(prj1),prob_annotation('SYMBOLIC')|I],multi/first_projection) :-
407 !,create_projection_set(A,B,first,Set).
408 cleanup_pre(second_projection(A,B),Type,I,Set,Type,[was(prj2),prob_annotation('SYMBOLIC')|I],multi/second_projection) :-
409 !,create_projection_set(A,B,second,Set).
410 cleanup_pre(event_b_first_projection(Rel),Type,I,Set,Type,[prob_annotation('SYMBOLIC')|I],multi/ev_first_projection) :-
411 !,create_event_b_projection_set(Rel,first,Set).
412 cleanup_pre(event_b_second_projection(Rel),Type,I,Set,Type,[prob_annotation('SYMBOLIC')|I],multi/ev_second_projection) :-
413 !,create_event_b_projection_set(Rel,second,Set).
414 cleanup_pre(event_b_first_projection_v2,Type,I,Set,Type,[prob_annotation('SYMBOLIC')|I],multi/ev2_first_projection) :-
415 !,create_event_b_projection_set_v2(Type,first,Set).
416 cleanup_pre(event_b_second_projection_v2,Type,I,Set,Type,[prob_annotation('SYMBOLIC')|I],multi/ev2_second_projection) :-
417 !,create_event_b_projection_set_v2(Type,second,Set).
418 cleanup_pre(image(Fun,SONE),T,I,Res,T,I,multi/succ_pred_image_optimisation) :-
419 singleton_set_extension(SONE,One), % succ[{h}] --> {h+1} and pred[{h}] --> {h-1} ; useful for alloy2b
420 precompute_pred_succ_function_call(Fun,One,FunOneRes),
421 !,
422 Res = set_extension([b(FunOneRes,integer,I)]).
423 cleanup_pre(union(Lambda1,Lambda2),T,I,lambda(TIDs1,TPred,TVal),T,I,multi/combine_lambdas_if_then_else) :-
424 Lambda1 = b(lambda(TIDs1,TPred1,TValue1),_,_), get_texpr_ids(TIDs1,Ids),
425 Lambda2 = b(lambda(TIDs2,TPred2,TValue2),_,_), get_texpr_ids(TIDs2,Ids),
426 % %x.(P & Cond1 | Val1) \/ %x.(P & not(Cond1) | Val2) ==> %x.(P| IF Cond1 THEN Val1 ELSE Val2 END)
427 conjunction_to_list(TPred1,L1),
428 conjunction_to_list(TPred2,L2),
429 append(Front1,[Last1],L1),
430 append(Front2,[Last2],L2),
431 maplist(same_texpr,Front1,Front2),
432 ? is_negation_of(Last1,Last2),
433 conjunct_predicates_with_pos_info(Front1,TPred),
434 get_texpr_type(TValue1,TV),
435 safe_create_texpr(if_then_else(Last1,TValue1,TValue2),TV,[],TVal),
436 (debug_mode(off) -> true
437 ; format('Union of lambdas converted to if-then-else: ',[]),
438 translate:print_bexpr(b(lambda(TIDs1,TPred,TVal),T,I)),nl
439 ).
440 cleanup_pre(event_b_comprehension_set(Ids,Expr,Pred),T,I,NewExpression,T,
441 [was(event_b_comprehension_set)|I],multi/ev_compset) :-
442 rewrite_event_b_comprehension_set(Ids,Expr,Pred, T, NewExpression).
443 cleanup_pre(domain_restriction(A,B),T,I,identity(A),T,I,multi/event_b_to_normal_identity1) :-
444 /* translate S <| id into id(S) */
445 is_event_b_identity(B).
446 cleanup_pre(range_restriction(B,A),T,I,identity(A),T,I,multi/event_b_to_normal_identity2) :-
447 /* translate id |> S into id(S) */
448 is_event_b_identity(B).
449 % what about translating id(TOTAL TYPE) into event_b_identity ??
450 cleanup_pre(ring(A,B),T,I,composition(B,A),T,I,multi/ring_composition). % replace backward composition by forward compositoin
451 cleanup_pre(less_equal(A,B),pred,I,less_equal_real(A,B),pred,I,multi/remove_ambiguous_leq_real) :-
452 get_texpr_type(A,real).
453 cleanup_pre(greater_equal(A,B),pred,I,less_equal_real(B,A),pred,I,multi/remove_ambiguous_geq_real) :-
454 get_texpr_type(A,real).
455 cleanup_pre(less(A,B),pred,I,less_real(A,B),pred,I,multi/remove_ambiguous_lt_real) :-
456 get_texpr_type(A,real).
457 cleanup_pre(greater(A,B),pred,I,less_real(B,A),pred,I,multi/remove_ambiguous_gt_real) :-
458 get_texpr_type(A,real).
459 cleanup_pre(unary_minus(A),real,I,unary_minus_real(A),real,I,multi/remove_ambiguous_unary_minus_real).
460 cleanup_pre(power_of(A,B),real,I,power_of_real(A,TB),real,I,multi/remove_ambiguous_unary_minus_real) :-
461 get_texpr_type(A,real),
462 safe_create_texpr(convert_real(B),real,[],TB). % TO DO: add pos
463 cleanup_pre(max(A),real,I,max_real(A),real,I,multi/remove_ambiguous_unary_max_real).
464 cleanup_pre(min(A),real,I,min_real(A),real,I,multi/remove_ambiguous_unary_min_real).
465 cleanup_pre(add(A,B),real,I,add_real(A,B),real,I,multi/remove_ambiguous_add_real).
466 cleanup_pre(div(A,B),real,I,div_real(A,B),real,I,multi/remove_ambiguous_div_real).
467
468 cleanup_pre(minus_or_set_subtract(A,B),integer,I,minus(A,B),integer,I,multi/remove_ambiguous_minus_int).
469 cleanup_pre(minus_or_set_subtract(A,B),real,I,minus_real(A,B),real,I,multi/remove_ambiguous_minus_real).
470 cleanup_pre(minus_or_set_subtract(A,B),Type,I,set_subtraction(A,B),Type,I,multi/remove_abiguous_minus_set) :-
471 is_set_type(Type,_).
472 cleanup_pre(mult_or_cart(A,B),integer,I,multiplication(A,B),integer,I,multi/remove_ambiguous_times_int).
473 cleanup_pre(mult_or_cart(A,B),real,I,multiplication_real(A,B),real,I,multi/remove_ambiguous_times_real).
474 cleanup_pre(mult_or_cart(A,B),Type,I,cartesian_product(A,B),Type,I,multi/remove_ambiguous_times_set) :-
475 is_set_type(Type,_).
476 cleanup_pre(E,T,Iin,E,T,Iout,multi/remove_rodinpos) :- % we use multi but can per construction only be applied once
477 selectchk(nodeid(rodinpos(_,[],_)),Iin,Iout). % remove rodinpos information with Name=[]
478 cleanup_pre(partition(X,[Set]),pred,I,equal(X,Set),pred,I,multi/remove_partition_one_element) :-
479 !,
480 % partition(X,Set) <=> X=Set
481 (debug_mode(off) -> true ;
482 print('Introducing equality for partition: '),
483 print_bexpr(X), print(' = '), print_bexpr(Set),nl).
484 cleanup_pre(case(Expression,CASES,Else),subst,I,NewSubst,subst,I,single/rewrite_case_to_if_then_else) :-
485 % translate CASE E OF EITHER e1 THEN ... ---> LET case_expr BE case_expr=E IN IF case_expr=e1 THEN ...
486 get_texpr_type(Expression,EType), get_texpr_info(Expression,EInfo),
487 ExprID = b(identifier(EID),EType,EInfo),
488 (get_texpr_id(Expression,EID)
489 -> NewSubst = if(IFLISTE) % no LET necessary
490 ; NewSubst = let([ExprID],Equal,b(if(IFLISTE),subst,I)),
491 get_unique_id_inside('case_expr',b(case(Expression,CASES,Else),subst,I),EID),
492 safe_create_texpr(equal(ExprID,Expression),pred,Equal)
493 ),
494 (maplist(gen_if_elsif(ExprID),CASES,IFLIST)
495 -> (get_texpr_expr(Else,skip) -> IFLISTE = IFLIST
496 ; TRUTH = b(truth,pred,[]), get_texpr_info(Else,EI),
497 append(IFLIST,[b(if_elsif(TRUTH,Else),subst,EI)],IFLISTE)
498 ),
499 (debug_mode(off) -> true
500 ; print('Translating CASE to IF-THEN-ELSE: '), print_bexpr(Expression),nl
501 %,translate:print_subst(b(NewSubst,subst,[])),nl
502 )
503 ; add_internal_error('Translation of CASE to IF-THEN-ELSE failed: ',CASES),fail
504 ).
505 cleanup_pre(exists(AllIds,Body),pred,I,exists(AllIds,Body),pred,I,single/check_implication_inside_exists) :-
506 is_an_implication(Body,LHS,_RHS),
507 % #x.(P => Q) is true if for some x P is false; usually one intends to write #x.(P & Q)
508 % see tests 1452, 1453 and 1493; Note: typing is always added by Rodin anyway
509 not_generated_exists_paras(AllIds),
510 Ex = b(exists(AllIds,Body),pred,I),
511 ( is_typing_predicate(LHS) % a typing predicate is equivalent to btrue; btrue => RHS is not problematic
512 -> true
513 ; animation_minor_mode(X),(X=eventb ; X=tla)
514 -> add_warning(bmachine_static_checks,'Body of existential quantifier is an implication: ',Ex,I)
515 ? ; member(removed_typing,I) % we have #x.(TYPE & (LHS => RHS)) and exists_body_warning has not triggered
516 -> add_warning(bmachine_static_checks,
517 'Body of existential quantifier corresponds to an implication (after removing typing predicates): ',Ex,I)
518 ; true % bmachine_construction:exists_body_warning already triggered and generated a warning already
519 ).
520 cleanup_pre(exists(AllIds,Body),pred,I0,NewP1,pred,NewI,single/components_partition_exists) :-
521 get_preference(optimize_ast,true),
522 nonmember(partitioned_exists,I0), % avoid re-computing components on something that is already partitioned
523 Simplify=no_cleanup_and_simplify, % avoid loops
524 % Warning: the next call may make use of existing used_ids infos; if they are wrong we may have a problem!
525 b_interpreter_components:construct_optimized_exists(AllIds,Body,NewPred,Simplify,NrC),
526 (NrC = 1 % just one component; perform no change to avoid re-ordering ids, ... ; see test 510
527 -> NewP1=exists(AllIds,Body), NewI=I0
528 ; get_texpr_ids(AllIds,Ids), sort(Ids,SortedIds),
529 add_important_infos_to_exists_conjuncts(NewPred,I0,SortedIds, b(NewP1,pred,NewI)),
530 % important e.g. for test 1945; in particular allow_to_lift_exists
531 % Note: construct_optimized_exists can lift unrelated inner exists out (/ClearSy/2023/perf_0704/rule_genz.mch)
532 (debug_mode(on), NewP1 \= exists(_,_)
533 -> format('PARTITIONED EXISTS:~n ',[]), translate:nested_print_bexpr(b(NewP1,pred,NewI)),nl ; true)
534 ).
535 cleanup_pre(exists(AllIds,P),pred,I,NewP1,pred,I,single/factor_out) :- % REDUNDANT with rule above ??
536 conjunction_to_nontyping_list(P,Preds),
537 % move things which do not depend on AllIds outside
538 % transform, e.g., #(x).(y>2 & x=y) --> y>2 & #(x).(x=y)
539 get_preference(optimize_ast,true),
540 create_exists_opt(AllIds,Preds,b(NewP1,pred,_I),Modified),
541 %(Modified = true -> print(exists(AllIds)),nl,print_bexpr(b(NewP1,pred,_I)),nl),
542 % the rule will fire again on the newly generated sub predicate ! -> fix ?
543 Modified=true.% check if anything modified; otherwise don't fire rule
544
545 cleanup_pre(exists(AllIds,P),pred,Info0,NewP,pred,INew,multi/remove_single_use_equality) :-
546 % remove existentially quantified variables which are defined by an equation and are used only once
547 % e.g., Z1...Z4 in not(#(X,Y,Z,Z1,Z2,Z3,Z4).(X:INTEGER & X*Y=Z1 & Z1*Z = Z2 & Z*X = Z3 & Z3*Y = Z4 & Z2 /= Z4))
548 get_preference(optimize_ast,true),
549 (length_less(AllIds,100) -> true % otherwise the code becomes quite inefficient at the moment
550 ; perfmessage('Large existential quantifier, performing limited optimizations',Info0),
551 fail),
552 conjunction_to_list(P,Preds),
553 CheckWellDef=no_check,
554 ? select_equality(TId,Preds,[],_,IDEXPR,RestPreds,_,CheckWellDef),
555 get_texpr_id(TId,ID),
556 ? select(TIdE,AllIds,RestIds), get_texpr_id(TIdE,ID),
557 can_be_optimized_away(TIdE),
558 \+ occurs_in_expr(ID,IDEXPR), % we cannot inline #x.(x=y+x & ...)
559 always_defined_full_check_or_disprover_mode(IDEXPR), % otherwise we may remove WD issue by removing ID if Count=0 or move earlier/later if count=1
560 single_usage_identifier(ID,RestPreds,Count), % we could also remove if Expr is simple
561 (Count=0 -> debug_println(19,unused_equality_id(ID)),
562 PL=RestPreds
563 ; % Count should be 1
564 conjunct_predicates_with_pos_info(RestPreds,RestPred),
565 ? replace_id_by_expr(RestPred,ID,IDEXPR,E2),
566 conjunction_to_list(E2,PL)
567 ),
568 create_exists_opt(RestIds,PL,TNewP), % no need to computed used ids yet; we could do this:
569 %conjunct_predicates_with_pos_info(PL,PP), safe_create_texpr(exists(RestIds,PP),pred,TNewP),
570 (debug_mode(off) -> true
571 ; format('Remove existentially quantified identifier with single usage: ~w (count: ~w)~n',[ID,Count]), print_bexpr(IDEXPR),nl),
572 TNewP = b(NewP,pred,INew),!.
573 cleanup_pre(exists(AllIds,P),pred,I,let_predicate(LetIds,Exprs,NewP),pred,INew,multi/exists_to_let) :-
574 % rewrite predicates of the form #x.(x=E & P(x)) into (LET x==E IN P(x))
575 % side condition for #(ids).(id=E & P(ids)): no identifiers of ids occur in E
576 get_preference(optimize_ast,true),
577 conjunction_to_nontyping_list(P,Preds), % TO DO: avoid recomputing again (see line in clause above)
578 % The ids are needed to build a "black list"
579 get_sorted_ids(AllIds,Ids),
580 find_one_point_rules(AllIds,Preds,Ids,LetIds,Exprs,RestIds,NewPreds),
581 % no_check is not ok in the context of existential quantification and reification:
582 % #x.(1:dom(f) & x=f(1) & P) --> LET x=f(1) IN 1:dom(f) & P END
583 % it is not ok if the whole predicate gets reified in b_intepreter_check !! Hence we use always_defined_full_check_or_disprover_mode; see Well_def_1.9.0_b5 in private_examples
584 % only succeed if we found at least one id which can be rewritten as let
585 LetIds = [ID1|_],
586 !,
587 (atomic(ID1) -> add_internal_error(cleanup_pre,unwrapped_let_identifier(ID1)), INew=I
588 ; get_texpr_ids(LetIds,AtomicIDs),
589 remove_used_ids_from_info(AtomicIDs,I,INew)
590 ), % probably not necessary ?!
591 % see also the annotate_toplevel_exists rule above which adds allow_to_lift_exists; relevant, e.g., for test 1945
592 ? (member(allow_to_lift_exists,I) -> AddInfos=[allow_to_lift_exists] ; AddInfos=[]),
593 create_exists_opt(RestIds,NewPreds,AddInfos,NewP,_Modified),
594 (debug_mode(off) -> true
595 ; format('Extracted LET over ~w from exists (rest: ~w):~n ',[AtomicIDs,RestIds]),
596 translate:print_bexpr(b(let_predicate(LetIds,Exprs,NewP),pred,I)),nl
597 ).
598 % now the same LET extraction but for universal quantification:
599 cleanup_pre(forall(AllIds,P,Rhs),pred,I,let_predicate(LetIds,Exprs,NewP),pred,I,multi/forall_to_let) :-
600 get_preference(optimize_ast,true),
601 conjunction_to_nontyping_list(P,Preds),
602 % The ids are needed to build a "black list"
603 get_sorted_ids(AllIds,Ids),
604 check_forall_lhs_rhs(P,Rhs,I,Ids),
605 find_one_point_rules(AllIds,Preds,Ids,LetIds,Exprs,RestIds,NewPreds),
606 % only succeed if we found at least one id which can be rewritten as let
607 LetIds = [ID1|_],!,
608 (atomic(ID1) -> add_internal_error(cleanup_pre,unwrapped_let_identifier(ID1)) ; true),
609 conjunct_predicates_with_pos_info(NewPreds,NewLhs),
610 create_implication(NewLhs,Rhs,NewForallBody),
611 create_forall(RestIds,NewForallBody,NewP),
612 (debug_mode(on) -> print('Introduced let in forall: '), print(LetIds),nl ; true).
613 % warning: used_identifier information not yet computed; translate may generate warnings
614 cleanup_pre(exists(AllIds,P),pred,I0,NewPE,pred,NewI,multi/exists_remove_typing) :-
615 (is_a_conjunct(P,Typing,Q) ; is_an_implication(P,Typing,Q)),
616 % TRUE & Q == TRUE => Q == Q
617 is_typing_predicate(Typing),
618 % remove typing so that other exists rules can fire
619 % we run as cleanup_pre: the other simplifications which remove typing have not run yet
620 % such typing conjuncts typicially come from Rodin translations
621 create_exists_opt(AllIds,[Q],b(NewPE,_,I1)),
622 add_important_info_from_super_expression(I0,I1,I2), % we could also copy node_id(_) from I0 ?
623 add_removed_typing_info(I2,NewI).
624 cleanup_pre(exists(AllIds,P),pred,I,disjunct(NewP1,NewP2),pred,I,single/partition_exists_implication) :-
625 is_a_disjunct_or_implication(P,_Type,Q,R),
626 /* note that even if R is only well-defined in case Q is false; it is ok to seperate this out
627 into two existential quantifiers: #x.(x=0 or 1/x=10) is ok to transform into #x.(x=0) or #x.(1/x=10) */
628 % this slows down test 1452, Cylinders, 'inv3/WD'; TO DO:investigate
629 create_exists_opt(AllIds,[Q],NewP1), % print('Q: '),print_bexpr(NewP1),nl,
630 create_exists_opt(AllIds,[R],NewP2). %, print('R: '),print_bexpr(NewP2),nl.
631 cleanup_pre(exists([B],P),pred,I,truth,pred,I,single/tautology_exists_min_max) :-
632 % ∃b·∀x0·(x0 ∈ FINITE ⇒ b ≤ x0) == TRUE : WD condition from Rodin for max; similar for min (TODO: check min)
633 B = b(identifier(ID1),integer,_),
634 get_texpr_expr(P,forall([X0],Left,Right)),
635 X0 = b(identifier(ID2),integer,_),
636 get_texpr_expr(Left,member(X1,FiniteSet)),
637 get_texpr_id(X1,ID2),
638 Right = b(COMP,pred,_),
639 (COMP = less_equal(B2,X2) ; COMP = greater_equal(B2,X2)),
640 get_texpr_id(B2,ID1), get_texpr_id(X2,ID2),
641 definitely_finite(FiniteSet),
642 (debug_mode(off) -> true ; format('Removing WD condition for min/max exists over ~w :',[ID1]), translate:print_bexpr(P),nl).
643 cleanup_pre(forall(AllIds,P,Rhs),pred,I,NewPred,pred,I,multi/forall_to_post_let) :-
644 % translate something like !(x,y).(y:1..100 & x=y*y => x<=y) into !(y).(y : 1 .. 100 => (#(x).( (x)=(y * y) & x <= y)))
645 post_let_forall(AllIds,P,Rhs,NewPred,modification),
646 !,
647 (debug_mode(on) -> print('POST LET INTRODUCTION: '), print_bexpr(b(NewPred,pred,[])),nl ; true).
648 cleanup_pre(set_extension(List),Type,I, set_extension(NList),Type,I, single/remove_pos) :-
649 remove_position_info_from_list(List,I,NList),!.
650 cleanup_pre(sequence_extension(List),Type,I, sequence_extension(NList),Type,I, single/remove_pos) :-
651 remove_position_info_from_list(List,I,NList),!.
652 cleanup_pre(if(List),Type,I, if(NList),Type,I, single/remove_if_elsif_pos) :-
653 % the pos info is not used for individual if_elsif entries; some models contain very large if-then-else constructs
654 maplist(remove_top_levelposition_info,List,NList),!.
655 %cleanup_pre(concat(A,B),string,I,Res,string,I,multi/concat_assoc_reorder) :-
656 % A = b(concat(A1,A2),string,I1),
657 % !, % reorder STRING concats for better efficiency, can only occur when allow_sequence_operators_on_strings is true
658 % % TO DO: extract information I2B from A2 and B
659 % Res = concat(A1,b(concat(A2,B),string,I2B)).
660 cleanup_pre(typeset,SType,I,Expr,SType,I,multi/remove_typeset) :- !,
661 % used, e.g., in test 1205 for recursive Event-B operator definition
662 ( ground(SType) ->
663 (is_set_type(SType,Type),
664 create_maximal_type_set(Type,b(MaxExpr,_,_)) -> Expr=MaxExpr
665 ; is_set_type(SType,Type) ->
666 add_error_and_fail(b_ast_cleanup,'Creating type expression for typeset failed: ',Type)
667 ;
668 add_error_and_fail(b_ast_cleanup,'Creating type expression for typeset failed, type is not a set: ',SType)
669 )
670 ; add_error_and_fail(b_ast_cleanup,'Non-ground type for typeset expression: ',SType)).
671 cleanup_pre(integer_set(S),Type,I,Expr,Type,[was(integer_set(S))|I],multi/remove_integer_set) :- !,
672 translate_integer_set(S,I,Expr),
673 (debug_mode(off) -> true
674 ; format('Rewrite ~w to: ',[S]),
675 print_bexpr(b(Expr,integer,I)),nl).
676 % should we move the rewrite_rules to normalize ??
677 cleanup_pre(Expr,Type,Info,NewExpr,NewType,NewInfo, multi/apply_rewrite_rule(Rule)) :-
678 ? rewrite_rule_with_rename(Expr,Type,Info,NewExpr,NewType,NewInfo,Rule), % from b_ast_cleanup_rewrite_rules
679 (debug_mode(off) -> true
680 ; format('Use rewrite_rule ~w~n',[Rule]),
681 print_bexpr(b(NewExpr,NewType,NewInfo)),nl),
682 (ground(NewExpr) -> true ; print(not_ground_rewrite(NewExpr)),nl,fail).
683 % 'x > y' to 'y < x'
684 cleanup_pre(greater(Lhs,Rhs), pred, I, less(Rhs,Lhs), pred, [was(greater(Lhs,Rhs))|I], single/normalize_greater) :-
685 preferences:get_preference(normalize_ast, true).
686 % 'x >= y' to 'y <= x'
687 cleanup_pre(greater_equal(Lhs,Rhs), pred, I, less_equal(Rhs,Lhs), pred, [was(greater_equal(Lhs,Rhs))|I], single/normalize_greater_equal) :-
688 preferences:get_preference(normalize_ast, true).
689 % 'x - y' to 'x + -y'
690 cleanup_pre(minus(Lhs,Rhs), integer, I, add(Lhs,b(unary_minus(Rhs),integer,[])), integer, [was(minus(Lhs,Rhs))|I], single/normalize_minus) :-
691 preferences:get_preference(normalize_ast, true).
692 cleanup_pre(value(CLOSURE), Type, I, comprehension_set(TIDs,B), Type, I, single/normalize_value_closure) :-
693 nonvar(CLOSURE), CLOSURE=closure(P,T,B),
694 preferences:get_preference(normalize_ast, true),
695 create_typed_ids(P,T,TIDs).
696 cleanup_pre(comprehension_set(TIDs,Body), Type, I, union(Set1,Set2), Type,I, single/extract_union) :-
697 preferences:get_preference(normalize_ast, true),
698 is_a_disjunct(Body,B1,B2), % should we also detect set difference, should we detect common prefix typing
699 % {x| P or Q} ==> {x|P} \/ {x|Q}
700 % such closure values are created by symbolic union, relevant for JSON trace replay for test 281
701 safe_create_texpr(comprehension_set(TIDs,B1),Type,I,Set1),
702 safe_create_texpr(comprehension_set(TIDs,B2),Type,I,Set2).
703 cleanup_pre(external_function_call('ASSERT_EXPR',[BOOL,MSG,EXPR]), Type, I,
704 assertion_expression(Pred,MsgStr,EXPR), Type,I, single/detect_assertion_expression) :-
705 % translate ASSERT_EXPR back to assertion_expression; dual to way it is printed in pretty printer
706 get_pred_from_bool(BOOL,Pred),
707 ? get_string(MSG,MsgStr).
708 cleanup_pre(external_pred_call(PRED,ARGS), pred, I,
709 EQ, pred,I, single/rewrite_external_pred_to_bool_function) :-
710 preferences:get_preference(normalize_ast,true),
711 synonym_for_external_predicate(PRED,FUNC),
712 % replace PRED(ARGS) by bool(FUNC(ARGS)=TRUE) as external functions can always be used wo DEFINITIONS
713 safe_create_texpr(external_function_call(FUNC,ARGS),boolean,[],FUNCALL),
714 EQ = equal(FUNCALL,b(boolean_true,boolean,[])),
715 (debug_mode(off) -> true ; print('REWRITTEN external predicate call to '), print_bexpr(FUNCALL),nl).
716
717
718 % Cleanup PRE for function calls:
719 % In reply to PROB-240: Check if arguments of Prj1/2 are types only using is_just_type:
720 cleanup_pre_function(TProjection,Argument,_Type,I,Result,I,multi/projection_call) :-
721 get_texpr_expr(TProjection,Projection),
722 cleanup_function_projection(Projection,Argument,I,Result),
723 !.
724 cleanup_pre_function(Lambda,Argument,Type,I,NewContextExpr,I,multi/lambda_guard1) :-
725 get_preference(optimize_ast,true),
726 get_texpr_expr(Lambda,LambdaExpr),
727 is_lambda_in_context(LambdaExpr,Type,TIds,TPre,TVal,NewContextExpr,NewExpr,LocalIds),
728 (is_just_typing_pred(TPre)
729 -> TPre1 = b(truth,pred,[]), % relevant for replace count below
730 get_texpr_expr(TVal,AssertionExpr)
731 ; TPre1=TPre,
732 AssertionExpr = assertion_expression(TPre1,ErrMsg,TVal)
733 ),
734 get_texpr_ids(TIds,Ids),
735 nested_couple_to_list(Argument,ArgList),
736 % translate %x.(TPre|TVal)(arg) -> LET x BE x=arg IN ASSERT_EXPR(TPre,Msg,TVal) END
737 same_length(ArgList,TIds),
738 \+ some_id_occurs_in_expr(LocalIds,Argument), % would trigger here LET x BE x=1+1 IN %y.(y:0..x|y+x+x) END (x) = res & x=0
739 ( same_ids_and_types(ArgList,TIds)
740 -> % lambda argument names and provided arguments are identical
741 NewExpr = AssertionExpr % no LET has to be introduced; relevant e.g. for rule_sgc335.mch
742 ; \+ ( sort(Ids,SIds),
743 some_id_occurs_in_expr(SIds,Argument)
744 %,format('Not inlining lambda, parameter id ~w occurs in : ',[Id]), print_bexpr(Argument),nl
745 %, add_message(ast_cleanup,'Not inlining parameter: ',Id,I)
746 ), % otherwise name clash and we would need a LET that can treat LET x BE x=x+1
747 TAssertionExpr = b(AssertionExpr,Type,I),
748 NewExpr = let_expression(TIds,ArgList,TAssertionExpr)
749 ; Ids = [Id1], ArgList = [Arg1] ->
750 %TODO: safely treat multiple args and things like (%(x,v).(x:INTEGER|x*v)(v|->v))=100
751 % In this case we need to substitute all args in one go
752 replace_id_by_expr_with_count(TPre1,Id1,Arg1,TPre2,Count1),
753 replace_id_by_expr_with_count(TVal,Id1,Arg1,TVal2,Count2),
754 Count is Count1+Count2,
755 ? is_replace_id_by_expr_ok(Arg1,Id1,Count,lambda_guard1),
756 NewExpr = assertion_expression(TPre2,ErrMsg,TVal2)
757 ),
758 % simplify_let will remove simple let expressions and vars used only once
759 % we used to call replace_ids_by_args in all cases, but this can duplicate arguments
760 % not replacing did lead to test 1284 taking very long, 191 seconds instead of 0.3 for 192 states
761 !,
762 ajoin_with_sep(Ids,',',IdsAtom),
763 get_texpr_info(Lambda,LambdaInfo), translate_span(LambdaInfo,LSpan),
764 (get_definition_context_from_span(LambdaInfo,LSpan2)
765 -> ajoin(['lambda function %(',IdsAtom,') ',LSpan,' (', LSpan2,
766 ') called outside of domain, condition false: '],ErrMsg)
767 ; ajoin(['lambda function %(',IdsAtom,') ',LSpan,
768 ' called outside of domain, condition false: '],ErrMsg)),
769 (debug_mode(off) -> true
770 ; add_message(ast_cleanup,'INLINED function application for: ',Ids,I),
771 translate:nested_print_bexpr(b(NewExpr,Type,I)),nl
772 ).
773 cleanup_pre_function(Fun,Arg,integer,I,ArithOp,NewI,multi/succ_pred_optimisation) :-
774 precompute_pred_succ_function_call(Fun,Arg,ArithOp),
775 delete(I,contains_wd_condition,NewI). % we no longer have a WD condition; succ/pred are totally defined
776 /* cleanup_pre(event_b_comprehension_set([ID],ID,Pred),T,I,comprehension_set([Result],NewPred),T,
777 [was(event_b_comprehension_set)|I],multi/ev_compset_single_id) :-
778 % Event_B_Comprehension with a single ID which is also the expression
779 % TO DO: expand for multiple IDs
780 !,
781 Result = ID, NewPred=Pred. */
782 % Detect if_then_else; also done in cleanup_post (in pre we may be able to detect IF-THEN-ELSE before CSE has inserted lazy_lets
783 cleanup_pre_function(IFT,DUMMYARG,_Type,Info,if_then_else(IFPRED,THEN,ELSE),Info,multi/function_if_then_else) :-
784 is_if_then_else(IFT,pre,DUMMYARG,IFPRED,THEN,ELSE),
785 (debug_mode(off) -> true
786 ; print('% Recognised if-then-else expression (pre): IF '), print_bexpr(IFPRED),
787 print(' THEN '),print_bexpr(THEN), print(' ELSE '), print_bexpr(ELSE),nl
788 ).
789
790 % check if we detect a lambda or a lambda wrapped inside let_expressions
791 % e.g., LET one BE one=1 IN LET two BE two=2 IN %(x).(x:INTEGER|x+one+one+two+two)END END(y) = 7
792 % NewType: by moving the function application into the LETs the type of the LETs need to be adapted
793 is_lambda_in_context(let_expression(LetIds,Exprs,b(Lambda,_OldType,Info)),NewType,TIds,TPred,TValue,
794 let_expression(LetIds,Exprs,b(InnerCtxt,NewType,Info)),Hole,NewLocalIds) :- !,
795 is_lambda_in_context(Lambda,NewType,TIds,TPred,TValue,InnerCtxt,Hole,LocalIds),
796 get_texpr_ids(LetIds,Ids),
797 sort(Ids,SIds),
798 ord_union(SIds,LocalIds,NewLocalIds).
799 is_lambda_in_context(Lambda,_NewType,TIds,TPred,TValue,Context,ReplacementHole,[]) :-
800 Context=ReplacementHole,
801 is_lambda(Lambda, TIds, TPred,TValue).
802
803 :- use_module(closures,[is_lambda_closure/7, is_lambda_comprehension_set/4]).
804 is_lambda(lambda(TIds,TPred,TValue), TIds, TPred,TValue) :- !.
805 is_lambda(event_b_comprehension_set([TId],Expr,TPred), [TId], TPred, TValue) :- !,
806 % rewrite_event_b_comprehension_set does not seem to get called before the function/lambda rule is applied
807 % {ID.ID|->Val | PRed}
808 Expr = b(couple(LHS,RHS),_,_),
809 same_texpr(LHS,TId),
810 TValue=RHS.
811 is_lambda(value(Closure),[TId],TPred,TValue) :- !, nonvar(Closure), Closure = closure(Args,Types,Body),
812 is_lambda_closure(Args,Types,Body, [OtherID], [OtherType], TPred, TValue),
813 create_typed_id(OtherID,OtherType,TId). % TODO: accept lambdas with more than one argument TId
814 is_lambda(CompSet,TIds,Pred,Val) :- CompSet=comprehension_set(_,_),
815 is_lambda_comprehension_set(b(CompSet,any,[]),TIds,Pred,Val).
816 is_just_typing_pred(b(member(_,B),pred,_)) :- is_just_type(B). % would be removed by remove_type_member rule
817
818
819 :- use_module(external_function_declarations,[synonym_for_external_predicate/2]).
820
821 get_string(b(string(S),_,_),S).
822 get_string(b(value(V),_,_),S) :- nonvar(V), V=string(Str), atom(Str), S=Str.
823 % translate a boolean value into a predicate:
824 get_pred_from_bool(b(convert_bool(P),_,_),Pred) :- !, Pred=P.
825 get_pred_from_bool(BOOL,b(equal(BOOL,BTRUE),pred,[])) :- BTRUE = b(boolean_true,boolean,[]).
826
827 translate_integer_set('NAT',I,interval(b(integer(0),integer,I),b(max_int,integer,I))).
828 translate_integer_set('NAT1',I,interval(b(integer(1),integer,I),b(max_int,integer,I))).
829 translate_integer_set('INT',I,interval(b(min_int,integer,I),b(max_int,integer,I))).
830 %translate_integer_set('INTEGER',I,comprehension_set([b(identifier('_zzzz_unary'),integer,I)],
831 % b(truth,pred,[prob_annotation('SYMBOLIC')|I]))).
832 %translate_integer_set('NATURAL',I,comprehension_set([b(identifier('_zzzz_unary'),integer,I)],
833 % b(greater_equal(b(identifier('_zzzz_unary'),integer,I),
834 % b(integer(0),integer,I)),pred,[prob_annotation('SYMBOLIC')|I]))).
835 %translate_integer_set('NATURAL1',I,comprehension_set([b(identifier('_zzzz_unary'),integer,I)],
836 % b(greater_equal(b(identifier('_zzzz_unary'),integer,I),
837 % b(integer(1),integer,I)),pred,[prob_annotation('SYMBOLIC')|I]))).
838
839 % detect if an expression is equivalent to an integer set, does not check for interval yet
840 is_integer_set(integer_set(S),S).
841 is_integer_set(comprehension_set([b(identifier(ID),integer,_)],b(B,_,_)),S) :-
842 ? is_integer_set_constraint_pred(B,ID,S).
843 is_integer_set_constraint_pred(truth,_,'INTEGER').
844 is_integer_set_constraint_pred(Expr,ID,Set) :-
845 is_greater_equal(Expr,b(identifier(ID),integer,_),TNr),
846 get_integer(TNr,Nr),
847 (Nr=0 -> Set='NATURAL' ; Nr=1 -> Set='NATURAL1').
848 is_integer_set_constraint_pred(Expr,ID,Set) :-
849 is_greater(Expr,b(identifier(ID),integer,_),TNr),
850 get_integer(TNr,Nr),
851 (Nr = -1 -> Set='NATURAL' ; Nr=0 -> Set='NATURAL1').
852
853 is_greater_equal(greater_equal(A,B),A,B).
854 is_greater_equal(less_equal(B,A),A,B).
855 is_greater(greater(A,B),A,B).
856 is_greater(less(B,A),A,B).
857
858 is_inf_integer_set_with_lower_bound(b(X,_,_),Bound) :- is_integer_set(X,N),
859 (N='NATURAL' -> Bound=0 ; N='NATURAL1' -> Bound=1).
860
861
862
863 is_subset(subset(A,B),A,B).
864 is_subset(member(A,b(pow_subset(B),_,_)),A,B). % x : POW(T) <=> x <: T
865
866 % tool to translate CASE values to Test predicates for IF-THEN-ELSE
867 gen_if_elsif(CaseID,b(case_or(ListOfValues, Body),_,I),
868 b(if_elsif(Test,Body),subst,I)) :-
869 get_texpr_type(CaseID,T),
870 SEXT = b(set_extension(ListOfValues),set(T),I),
871 Test = b(member(CaseID,SEXT),pred,I).
872
873 % the case below happens frequently in data validation:
874 remove_position_info_from_list(List,I,NList) :-
875 member(nodeid(pos(C,FilePos,Line,From,Line,To)),I),
876 To-From > 1000, % the entire set/sequence extension is on one large line
877 length(List,Len), Len>100, % it has many elements
878 % we replace all position infos by the same top-level position info (enabling sharing)
879 maplist(remove_position_info(nodeid(pos(C,FilePos,Line,From,Line,To))),List,NList),
880 (debug_mode(off) -> true
881 ; format('SIMPLIFY POSITION INFO IN SET/SEQUENCE EXTENSION: line # ~w, length ~w~n',[Line,Len])).
882 remove_position_info(NI,b(Expr,Type,Infos),b(NExpr,Type,NewInfos)) :-
883 syntaxtransformation(Expr,Subs,_Names,NSubs,NExpr),
884 (select(nodeid(pos(_,_FilePos,_,_,_,_)),Infos,NT) -> NewInfos=[NI|NT] ; NewInfos=Infos),
885 maplist(remove_position_info(NI),Subs,NSubs).
886
887 :- use_module(bsyntaxtree,[delete_pos_info/2]).
888 % just remove position infos from top-lefel
889 remove_top_levelposition_info(b(Expr,Type,Infos),b(Expr,Type,NewInfos)) :-
890 delete_pos_info(Infos,NewInfos). % TODO: maybe remove other useless infos
891
892 % rules for function application of various projection functions
893 cleanup_function_projection(first_projection(A,B),Argument,I,Result) :-
894 gen_assertion_expression(A,B,Argument,first_of_pair(Argument),first,I,Result).
895 cleanup_function_projection(second_projection(A,B),Argument,I,Result) :-
896 gen_assertion_expression(A,B,Argument,second_of_pair(Argument),second,I,Result).
897 cleanup_function_projection(event_b_second_projection(A),Argument,_I,Result) :- % old style Rodin projection
898 check_is_just_type(A),Result = first_of_pair(Argument).
899 cleanup_function_projection(event_b_second_projection(A),Argument,_I,Result) :- % old style Rodin projection
900 check_is_just_type(A),Result = second_of_pair(Argument).
901 cleanup_function_projection(event_b_first_projection_v2,Argument,_I,Result) :- Result = first_of_pair(Argument).
902 cleanup_function_projection(event_b_second_projection_v2,Argument,_I,Result) :- Result = second_of_pair(Argument).
903
904 check_is_just_type(_A) :- preferences:get_preference(ignore_prj_types,true),!.
905 check_is_just_type(A) :- (is_just_type(A) -> true ; debug_println(9,not_type_for_prj(A)),fail).
906
907 :- use_module(bsyntaxtree,[get_texpr_set_type/2, create_cartesian_product/3]).
908 gen_assertion_expression(A,B,_Argument,ProjExpr,_ProjType,_I,Result) :-
909 check_is_just_type(A),check_is_just_type(B),
910 !,
911 Result = ProjExpr.
912 % TO DO: add simplification rule for couple(x,y) : A*B with A or B being just types
913 gen_assertion_expression(A,B,Argument,ProjExpr,ProjType,Info,Result) :-
914 create_cartesian_product(A,B,CartAB),
915 safe_create_texpr(member(Argument,CartAB),pred,MemCheck),
916 ErrMsg = 'projection function called outside of domain: ', % TO DO: provide better user message with Argument result
917 perfmessage('Projection function has WD condition which needs to be checked at runtime (use prj1/prj2 without arguments or set IGNORE_PRJ_TYPES preference to TRUE)',Info),
918 (ProjType == first -> get_texpr_set_type(A,TT) ; get_texpr_set_type(B,TT)), %%
919 %get_texpr_pos_infos(Argument,Info), % add position infos
920 extract_pos_infos(Info,PosInfo),
921 safe_create_texpr(ProjExpr,TT,PosInfo,TProjExpr),
922 Result = assertion_expression(MemCheck,ErrMsg,TProjExpr).
923
924
925
926 % rewriting Event-B comprehension sets into classical B style ones
927 rewrite_event_b_comprehension_set(IDs,CoupleExpr,Pred, _T, NewExpression) :-
928 % detect lambda expressions in classical B style
929 nested_couple_to_list(CoupleExpr,List),
930 check_ids(IDs,List,Expr),!,
931 NewExpression = lambda(IDs,Pred,Expr).
932 rewrite_event_b_comprehension_set(IDList,CoupleExpr,Pred, _T, NewExpression) :-
933 % Event_B_Comprehension with a several IDs which are also used as the couple expression
934 nested_couple_to_list(CoupleExpr,List),
935 List = IDList,
936 !,
937 NewExpression = comprehension_set(IDList,Pred).
938 rewrite_event_b_comprehension_set(Ids,Expr,Pred, T, NewExpression) :-
939 NewExpression = comprehension_set([Result],NewPred),
940 unify_types_strict(T,set(Type)),
941 % print(event_b_comprehension_set(Ids,Expr,Pred)),nl,
942 ? (select(Expr,Ids,RestIds)
943 -> % the Expr is an identifier which is part of Ids: we can avoid complicated translation below
944 % example {f,n•n:INT & f:1..n-->Digit|f} --translated-> {f|#(n).(n:INT & f:1..n-->Digit)}
945 % print(remove(Expr,RestIds)),nl,
946 ExPred=Pred, Result=Expr
947 ; get_unique_id_inside('__comp_result__',Pred,Expr,ResultId),
948 create_texpr(identifier(ResultId),Type,[],Result),
949 safe_create_texpr(equal(Result,Expr),pred,Equal),
950 conjunct_predicates_with_pos_info(Pred,Equal,ExPred), % put Equal after Pred for WD; used to be other order!
951 RestIds=Ids
952 ),
953 create_exists(RestIds,ExPred,NewPred). %, print(done_rewrite_event_b_comprehension_set),nl, print_bexpr(NewPred),nl.
954
955 check_ids([],[CoupleExpr],CoupleExpr). % we terminate with a single expression
956 check_ids([ID|T],[CoupleExprID|CT],Rest) :-
957 same_id(ID,CoupleExprID,_),
958 check_ids(T,CT,Rest).
959
960
961 evaluate_seq_extension_to_avl(List,AVL,LocalIds) :-
962 evaluate_set_extension(List,EvaluatedList,LocalIds),
963 convert_set_to_seq(EvaluatedList,1,ESeq),
964 convert_to_avl(ESeq,AVL).
965
966 evaluate_set_extension([],[],_).
967 evaluate_set_extension([H|List],[EH|EvaluatedList],LocalIds) :-
968 eval_set_extension_element(H,EH,LocalIds),
969 evaluate_set_extension(List,EvaluatedList,LocalIds).
970
971 extension_should_be_evaluated(List) :-
972 %preferences:has_default_value(use_solver_on_load), % Kodkod could not translate booleans back; now it can; check if we still need this
973 preferences:get_preference(optimize_ast,true),
974 List \= [],
975 List = [_|ListT], ListT \= []. % do not do this for singleton sets so as not to prevent triggering of other rules
976
977 :- use_module(kernel_reals,[construct_real/2, construct_negative_real/2]).
978 % construct a value term for a simple AST element:
979 eval_set_extension_element(b(E,T,_I),EE,LocalIds) :-
980 (eval_set_extension_aux(E,EE,LocalIds) -> true
981 ; eval_set_extension_typed_aux(E,T,EE,LocalIds)
982 % ; print('eval_set_extension failed: '),tools_printing:print_term_summary(E),nl,translate:print_span(_I),nl,fail
983 ).
984 eval_set_extension_aux(boolean_false,pred_false,_).
985 eval_set_extension_aux(boolean_true,pred_true,_).
986 eval_set_extension_aux(couple(A,B),(EA,EB),LocalIds) :-
987 eval_set_extension_element(A,EA,LocalIds), eval_set_extension_element(B,EB,LocalIds).
988 eval_set_extension_aux(integer(I),int(I),_).
989 eval_set_extension_aux(real(Atom),Real,_) :- construct_real(Atom,Real).
990 eval_set_extension_aux(unary_minus(b(Val,_,_)),Res,_) :- eval_set_ext_minus(Val,Res).
991 eval_set_extension_aux(string(S),string(S),_).
992 eval_set_extension_aux(empty_set,[],_).
993 eval_set_extension_aux(empty_sequence,[],_).
994 eval_set_extension_aux(value(V),V,_).
995 eval_set_extension_aux(rec(Fields),rec(EF),LocalIds) :- eval_set_extension_fields(Fields,EF,LocalIds).
996 %eval_set_extension_aux(interval(A,B),...) :- ...
997 eval_set_extension_aux(set_extension(List),AVL,LocalIds) :-
998 evaluate_set_extension(List,EvaluatedList,LocalIds),
999 convert_to_avl(EvaluatedList,AVL).
1000 eval_set_extension_aux(sequence_extension(List),AVL,LocalIds) :-
1001 evaluate_seq_extension_to_avl(List,AVL,LocalIds).
1002
1003
1004 :- use_module(probsrc(kernel_freetypes),[registered_freetype_case_value/3, freetype_case_db/3]).
1005 eval_set_extension_typed_aux(identifier(ID),TYPE,FDVal,LocalIds) :- LocalIds \= not_available,
1006 (TYPE = global(GType)
1007 -> b_global_sets:lookup_global_constant(ID,FDVal),
1008 ord_nonmember(ID,LocalIds),
1009 % we could check if enumerated_set_element entry in infos, cf is_just_type3 with given_set info
1010 % may not yet be fully precompiled, hence we rely on pre_register_enumerated_set_with_elems
1011 FDVal = fd(_,GType) % just check that the type matches, in case ID is a local name with different type
1012 ; TYPE = freetype(FType)
1013 -> % see b_global_set_or_free_type; we could also accept global sets and freetype sets
1014 registered_freetype_case_value(ID,TYPE,FDVal),
1015 ord_nonmember(ID,LocalIds),
1016 FDVal = freeval(FType,_,_) % check type matches
1017 ).
1018 eval_set_extension_typed_aux(function(TID,Args),freetype(FreetypeId),V,LocalIds) :- LocalIds \= not_available,
1019 ground(FreetypeId),
1020 get_texpr_id(TID,CaseId),
1021 freetype_case_db(CaseId,FreetypeId,_CaseType),
1022 ord_nonmember(CaseId,LocalIds),
1023 %write(case(CaseId,FreetypeId,CaseType)),nl,
1024 eval_set_extension_element(Args,EArgs,LocalIds),
1025 V = freeval(FreetypeId,CaseId,EArgs).
1026 %eval_set_extension_typed_aux(E,T,_,_) :- print(uncov(E,T)),nl,nl,fail.
1027
1028
1029 eval_set_ext_minus(integer(I),int(R)) :- R is -I.
1030 eval_set_ext_minus(real(Atom),Real) :- construct_negative_real(Atom,Real).
1031
1032 eval_set_extension_fields([],[],_LocalIds).
1033 eval_set_extension_fields([field(Name,V)|T],[field(Name,EV)|ET],LocalIds) :- eval_set_extension_element(V,EV,LocalIds),
1034 eval_set_extension_fields(T,ET,LocalIds).
1035
1036 convert_set_to_seq([],_,[]).
1037 convert_set_to_seq([H|T],N,[(int(N),H)|CT]) :- N1 is N+1, convert_set_to_seq(T,N1,CT).
1038
1039
1040 post_let_forall(AllIds,P,Rhs,NewPred,modification) :-
1041 conjunction_to_list(P,Preds), reverse(Preds,RPreds),
1042 ? select_equality(TId,RPreds,[],_,Expr,RRest,UsedIds,no_check),
1043 ? select(TId,AllIds,RestIds),
1044 get_texpr_id(TId,Id),
1045 \+ member(Id,UsedIds), % not a recursive equality
1046 reverse(RRest,Rest),
1047 conjunct_predicates_with_pos_info(Rest,RestPred),
1048 \+ occurs_in_expr(Id,RestPred),
1049 !,
1050 NewRhs = b(let_predicate([TId],[Expr],Rhs),pred,[]),
1051 post_let_forall(RestIds,RestPred,NewRhs,NewPred,_).
1052 post_let_forall(AllIds,P,Rhs,NewPred, no_modification) :-
1053 create_implication(P,Rhs,NewForallBody),
1054 create_forall(AllIds,NewForallBody,NewP),
1055 get_texpr_expr(NewP,NewPred).
1056
1057
1058 is_interval(b(interval(A,B),_,_),A,B).
1059 is_interval(b(value(V),set(_),_),A,B) :- nonvar(V), V=closure(P,T,B),
1060 custom_explicit_sets:is_interval_closure(P,T,B,LOW,UP), integer(LOW),integer(UP),
1061 A=b(integer(LOW),integer,[]),
1062 B=b(integer(UP),integer,[]).
1063
1064 % a more flexible version, also detecting singleton set extension
1065 ?is_interval_or_singleton(I,A,B) :- is_interval(I,A,B),!.
1066 is_interval_or_singleton(b(set_extension([A]),set(integer),_),A,A).
1067
1068
1069
1070 % create a lambda expression for a projection
1071 create_projection_set(A,B,_Switch,Res) :-
1072 (definitely_empty_set(A) ; definitely_empty_set(B)),!,
1073 Res = empty_set.
1074 create_projection_set(A,B,Switch,lambda(Ids,SPred,Expr)) :- % generate lambda to be able to use function(lambda) rule
1075 Ids = [TArg1,TArg2],
1076 ( Switch==first -> Expr = TArg1
1077 ; Switch==second -> Expr = TArg2),
1078 get_texpr_type(A,TA1), unify_types_strict(TA1,set(Type1)),
1079 get_texpr_type(B,TB2), unify_types_strict(TB2,set(Type2)),
1080 ? (contains_no_ids(A,B) -> Arg1 = '_zzzz_unary', Arg2 = '_zzzz_binary' % avoid generating fresh ids; relevant for test 1313 and ticket PROB-346
1081 % TO DO: check whether _zzzz_unary/binary are actually used; we should avoid generating fresh ids whenever possible (otherwise syntactically identical formulas become different)
1082 ; get_unique_id_inside('_prj_arg1__',A,B,Arg1),
1083 get_unique_id_inside('_prj_arg2__',A,B,Arg2)),
1084 create_texpr(identifier(Arg1),Type1,[generated(Switch)],TArg1),
1085 create_texpr(identifier(Arg2),Type2,[generated(Switch)],TArg2),
1086 safe_create_texpr(member(TArg1,A),pred,MembA),
1087 safe_create_texpr(member(TArg2,B),pred,MembB),
1088 conjunct_predicates([MembA,MembB],Pred), SPred=Pred.
1089 % bsyntaxtree:mark_bexpr_as_symbolic(Pred,SPred). % TO DO: put mark code into another module; maybe only mark as symbolic if types large enough ??
1090
1091 ?contains_no_ids(A,B) :- contains_no_ids(A), contains_no_ids(B).
1092 ?contains_no_ids(b(E,_,_)) :- contains_no_ids_aux(E).
1093 contains_no_ids_aux(bool_set).
1094 contains_no_ids_aux(X) :- is_integer_set(X,_). % comprehension set may contain ids, but not visible to outside
1095 contains_no_ids_aux(mult_or_cart(A,B)) :- contains_no_ids(A),contains_no_ids(B).
1096 contains_no_ids_aux(relations(A,B)) :- contains_no_ids(A),contains_no_ids(B).
1097 contains_no_ids_aux(pow_subset(A)) :- contains_no_ids(A).
1098 contains_no_ids_aux(pow1_subset(A)) :- contains_no_ids(A).
1099 contains_no_ids_aux(real_set).
1100 contains_no_ids_aux(string_set).
1101 contains_no_ids_aux(interval(A,B)) :- contains_no_ids(A),contains_no_ids(B).
1102 % TO DO: add more
1103
1104 create_event_b_projection_set(Rel,Switch,lambda(Ids,SPred,Expr)) :-
1105 Ids = [TArg1,TArg2],
1106 ( Switch==first -> Expr = TArg1
1107 ; Switch==second -> Expr = TArg2),
1108 get_texpr_type(Rel,RT),unify_types_strict(RT,set(couple(Type1,Type2))),
1109 get_unique_id_inside('_prj_arg1__',Rel,Arg1),
1110 get_unique_id_inside('_prj_arg2__',Rel,Arg2),
1111 create_texpr(identifier(Arg1),Type1,[generated(Switch)],TArg1),
1112 create_texpr(identifier(Arg2),Type2,[generated(Switch)],TArg2),
1113 create_texpr(couple(TArg1,TArg2),couple(Type1,Type2),[],Couple),
1114 safe_create_texpr(member(Couple,Rel),pred,Member),
1115 SPred=Member.
1116 %bsyntaxtree:mark_bexpr_as_symbolic(Pred,SPred).
1117
1118 create_event_b_projection_set_v2(RelType,Switch,comprehension_set(Ids,SPred)) :-
1119 % we are generating {p1,p2,lambda | lambda=p1/p2}
1120 Ids = [TArg1,TArg2,TArg3],
1121 ( Switch==first -> ResultExpr = TArg1, Type1 = Type3
1122 ; Switch==second -> ResultExpr = TArg2, Type2 = Type3),
1123 unify_types_strict(RelType,set(couple(couple(Type1,Type2),T3))),
1124 (T3==Type3 -> true ; add_error(create_event_b_projection_set,'Unexpected return type: ',T3)),
1125 Arg1 = '_zzzz_unary',
1126 Arg2 = '_zzzz_binary',
1127 Arg3 = '_lambda_result_', % the comprehension set contains no other expressions: no clash possible
1128 create_texpr(identifier(Arg1),Type1,[generated(Switch)],TArg1),
1129 create_texpr(identifier(Arg2),Type2,[generated(Switch)],TArg2),
1130 create_texpr(identifier(Arg3),Type3,[lambda_result(Arg3),generated(Switch)],TArg3),
1131 safe_create_texpr(equal(TArg3,ResultExpr),pred,[prob_annotation('LAMBDA-EQUALITY')],Equal),
1132 SPred=Equal.
1133 % bsyntaxtree:mark_bexpr_as_symbolic(Pred,SPred).
1134 %,print(Pred),nl.
1135
1136 :- use_module(btypechecker,[couplise_list/2,prime_identifiers/2,prime_identifiers0/2, prime_atom0/2]).
1137 % create a comprehension set for quantified union or intersection UNION(x).(P|E) = ran(%x.(P|E))
1138 % TO DO: translate UNION into UNION(x).(P|E) = dom({r,x|P & r:E}) = ran({x,r|P & r:E}) which is considerably faster
1139 % also works for e.g., UNION(x).(x:1..2|{x+y}) = 12..13
1140 %quantified_union_op(Ids,Pred,Expr,SetType,Res) :- is_set_type(SetType,Type),
1141 % !,
1142 % Info = [generated(quantified_union)],
1143 % get_unique_id_inside('_zzzz_unary',Pred,Expr,FRESHID), % also include Expr !
1144 % NewID = b(identifier(FRESHID),Type,[]), %fresh
1145 % append(Ids,[NewID],NewIds),
1146 % safe_create_texpr(member(NewID,Expr),pred,[],Member),
1147 % conjunct_predicates([Pred,Member],Body),
1148 % get_texpr_types(NewIds,Types),couplise_list(Types,TupleType),
1149 % safe_create_texpr(comprehension_set(NewIds,Body),set(TupleType),Info,ComprSet),
1150 % Res = range(ComprSet).
1151 % %safe_create_texpr(range(ComprSet),set(set(Type)),Info,Set), print_bexpr(Set),nl.
1152 %quantified_union_op(Ids,Pred,Expr,SetType,Set) :-
1153 % add_internal_error('Could not translate quantified UNION operator: ',quantified_union_op(Ids,Pred,Expr,SetType,Set)),
1154 % fail.
1155
1156 % create a comprehension set for quantified union or intersection INTER(x).(P|E) = inter(ran(%x.(P|E)))
1157 % UNION could be treated by quantified_union_op above
1158 quantified_set_op(Ids,Pred,Expr,Loc,OuterInfos,Set) :-
1159 create_range_lambda(Ids,Pred,Expr,Loc,OuterInfos,Set),
1160 !. % , print(quantified),nl,print_bexpr(Set),nl.
1161 quantified_set_op(Ids,Pred,Expr,Loc,OuterInfos,Set) :-
1162 add_internal_error('Could not translate quantified set operator: ',
1163 quantified_set_op(Ids,Pred,Expr,Loc,OuterInfos,Set)),
1164 fail.
1165
1166 create_range_lambda(Ids,Pred,Expr,Loc,OuterInfos,Set) :-
1167 Info = [generated(Loc)|OuterInfos],
1168 get_texpr_types(Ids,Types),couplise_list(Types,ArgType),
1169 get_texpr_type(Expr,ExprType),
1170 safe_create_texpr(lambda(Ids,Pred,Expr),set(couple(ArgType,ExprType)),Info,Lambda),
1171 safe_create_texpr(range(Lambda),set(ExprType),Info,Set).
1172
1173
1174 quantified_set_operator(quantified_union(AllIds,Pred,Expr),quantified_union,AllIds,Pred,Expr).
1175 quantified_set_operator(quantified_intersection(AllIds,Pred,Expr),quantified_intersection,AllIds,Pred,Expr).
1176
1177 % match_ids(List1,List2, AllIds,Rest) find all ids in List1 in List2; ids in List2 not in List1 are put in Rest
1178 match_ids([],List,List,List).
1179 ?match_ids([TID|T],List,[TID2|T2],Rest) :- select(TID2,List,L2),
1180 same_id(TID,TID2,_),!,
1181 match_ids(T,L2,T2,Rest).
1182
1183 % generate dom(.) operators for TypedIds which have to be projected away
1184 generate_dom_for_ids([],E,T,I,b(E,T,I)).
1185 generate_dom_for_ids([TID|Ts],E,T,I,Res) :- T = set(T1),
1186 get_texpr_type(TID,TIDType),
1187 generate_dom_for_ids(Ts,E,set(couple(T1,TIDType)),I,DE),
1188 safe_create_texpr(domain(DE),T,Res).
1189
1190 :- use_module(tools_strings,[ajoin/2,ajoin_with_sep/3]).
1191 % we ensure that this check is only done once, for user machines,... not for generated formulas
1192 check_forall_lhs_rhs(_,_,_,_) :- preferences:get_preference(perform_stricter_static_checks,false),!.
1193 check_forall_lhs_rhs(_,_,_,_) :- preferences:get_preference(disprover_mode,true),!.
1194 check_forall_lhs_rhs(_,_,_,_) :- animation_minor_mode(eventb),!. % typing predicates get removed it seems
1195 ?check_forall_lhs_rhs(_,_,I,_) :- member(removed_typing,I),!. % means that typing was possibly removed
1196 ?check_forall_lhs_rhs(Lhs,_,_,_) :- member_in_conjunction(PC,Lhs),
1197 ? get_texpr_info(PC,PI),member(II,PI),
1198 removed_typing(II),!. % it was something else; does not seem to detect all removed conjunctions, hence we also check I above
1199 check_forall_lhs_rhs(P,_,I,Ids) :- find_identifier_uses_if_necessary(P,[],LhsUsed),
1200 ord_subtract(Ids,LhsUsed,NotDefined),
1201 NotDefined=[_|_],
1202 ajoin_with_sep(NotDefined,',',S),
1203 translate:translate_bexpression(P,PS),
1204 ajoin(['Left-hand side "', PS, '" of forall does not define identifier(s): '],Msg),
1205 add_warning(bmachine_static_checks,Msg,S,I),
1206 fail.
1207 check_forall_lhs_rhs(_,Rhs,I,Ids) :-
1208 find_identifier_uses_if_necessary(Rhs,[],RhsUsed),
1209 (ord_intersect(Ids,RhsUsed) -> true
1210 ; ajoin_with_sep(Ids,',',S),
1211 add_warning(bmachine_static_checks,'Right-hand side of forall does not use identifiers: ',S,I)
1212 ).
1213 removed_typing(removed_typing). removed_typing(was(_)).
1214
1215 :- use_module(kernel_records,[normalise_record_type/2]).
1216 :- use_module(library(lists),[last/2]).
1217
1218 % first the rules that require the path:
1219 cleanup_post_with_path(assign([b(identifier(ID),TYPE,INFO)],[EXPR]),subst,I,
1220 assign_single_id(b(identifier(ID),TYPE,INFO),EXPR),subst,I,single/assign_single_id,Path) :-
1221 \+ animation_minor_mode(eventb), % there is no support in the Event-B interpreter for assign_single_id yet
1222 ? (simple_expression(EXPR) % the assign_single_id is not guarded by a waitflag; EXPR should not be too expensive too calculate
1223 -> true
1224 ; % if we are in an unguarded context; then we do not need to guard EXPR by waitflag anyway
1225 ? maplist(unguarded,Path)
1226 ),
1227 !,
1228 (debug_level_active_for(4) -> format('Single Assignment to ~w~n',[ID])
1229 %translate:print_subst(b(assign([b(identifier(ID),TYPE,INFO)],[EXPR]),subst,I)),nl
1230 ; true).
1231 cleanup_post_with_path(any(Ids,Pred,Subst),subst,Info,any(Ids,Pred,NewSubst),subst,NewInfo,multi/remove_useless_assign,_Path) :-
1232 get_preference(optimize_ast,true),
1233 ? member_in_conjunction(b(equal(TID1,TID2),pred,_),Pred),
1234 get_texpr_id(TID1,ID1),
1235 get_texpr_id(TID2,ID2), % we have an equality of the form x=x' (as generated by TLA2B)
1236 ? delete_assignment(Subst,TID3,TID4,NewSubst),
1237 get_texpr_id(TID4,ID4), get_texpr_id(TID3,ID3),
1238 ( c(ID1,ID2) = c(ID3,ID4) ; c(ID1,ID2) = c(ID4,ID3)), % we have an assignment x:=x' or x':=x
1239 % the cleanup rule recompute_accessed_vars below recomputes the info fields for enclosing operations! get_accessed_vars is currently called before ast_cleanup
1240 ajoin([ID3,' := ',ID4],Assign),
1241 add_hint_message(remove_useless_assign,'Removing useless assignment: ',Assign,Info),
1242 ? (member(removed_useless_assign,Info) -> NewInfo=Info ; NewInfo=[removed_useless_assign|Info]).
1243 cleanup_post_with_path(operation(TName,Res,Params,TBody),Type,Info,
1244 operation(TName,Res,Params,NewTBody),Type,NewInfos,single/recompute_accessed_vars,_Path) :-
1245 TBody=b(Body,subst,BInfos),
1246 ? select(removed_useless_assign,BInfos,NewBInfos),
1247 btypechecker:compute_accessed_vars_infos_for_operation(TName,Res,Params,TBody,Modifies,_,_,_,NewRWInfos),
1248 debug_format(19,'Recomputing read/write infos for ~w (~w)~n',[TName,Modifies]),
1249 update_infos(NewRWInfos,Info,NewInfos),
1250 NewTBody=b(Body,subst,NewBInfos).
1251 cleanup_post_with_path(any(Ids,Pred,Subst),subst,I,Result,subst,[generated|I],single/transform_any_into_let,Path) :-
1252 (last(Path,path_arg(top_level(_),_))
1253 /* do not remove top-level ANY if show_eventb_any_arguments is true; see, e.g., test 1271 */
1254 -> preferences:preference(show_eventb_any_arguments,false) ; true),
1255 conjunction_to_list(Pred,Preds),
1256 get_sorted_ids(Ids,BlacklistIds),
1257 find_one_point_rules(Ids,Preds,BlacklistIds,LetIDs,Exprs,RestIds,RestPreds),
1258 LetIDs \= [],
1259 maplist(create_equality,LetIDs,Exprs,LetDefs),
1260 % print(found_lets(LetIDs,RestIds,RestPred)),nl,print(Path),nl,
1261 conjunct_predicates_with_pos_info(LetDefs,LetDefPred),
1262 (RestIds = [], RestPreds=[] % complete ANY can be translated to LET
1263 -> Result = let(LetIDs,LetDefPred,Body), Body = Subst
1264 ? ; split_predicates(RestPreds,Ids,RestUsingIds,RestNotUsingIds),
1265 conjunct_predicates_with_pos_info(RestPreds,RestPred),
1266 % print('USING: '), print_bexpr(RestUsingIds),nl, print('NOT USING: '), print_bexpr(RestNotUsingIds),nl,
1267 (RestIds = []
1268 -> (is_truth(RestUsingIds)
1269 % RestPred does not use the LET identifiers; move outside of the LET !
1270 -> Result = select([b(select_when(RestPred,SelectBody),subst,[generated|I])]),
1271 SelectBody = b(let(LetIDs,LetDefPred,Subst),subst,[generated|I])
1272 ; is_truth(RestNotUsingIds)
1273 % RestPred uses LET identifiers in all conjuncts; move inside LET
1274 -> Result = let(LetIDs,LetDefPred,LetBody),
1275 LetBody = b(select([b(select_when(RestPred,Subst),subst,[])]),subst,[generated|I])
1276 ;
1277 % we would need to generate an outer and inner select; transformation probably not worth it
1278 fail
1279 )
1280 ; is_truth(RestUsingIds)
1281 % RestPred does not use LET identifiers move outside of LET
1282 -> Result = any(RestIds,RestPred,SelectBody),
1283 SelectBody = b(let(LetIDs,LetDefPred,Subst),subst,[generated|I])
1284 ; is_truth(RestNotUsingIds)
1285 % RestPred uses LET identifiers in all conjuncts; move inside LET
1286 -> Result = let(LetIDs,LetDefPred,LetBody),
1287 LetBody = b(any(RestIds,RestPred,Subst),subst,I)
1288 ;
1289 % we would need to generate an outer and inner any; transformation probably not worth it
1290 fail
1291 )
1292 ),
1293 !. %,translate:print_subst(b(Result,subst,[])),nl.
1294 cleanup_post_with_path(operation(TName,Res,Params,Body),Type,Info,
1295 operation(TName,Res,Params,NewBody),Type,Info,single/lts_min_guard_splitting,Path) :-
1296 get_preference(ltsmin_guard_splitting,true), % used also to checkpge_algo:is_pge_opt_on,
1297 Path = [path_arg(top_level(operation_bodies),_)], % only apply at top-level and TO DO: only for top-most machine !!
1298 % TO DO: also apply for Event-B models
1299 get_texpr_id(TName,Name),
1300 (get_operation_propositional_guards(Name,Res,Params,Body,Guards,RestBody)
1301 -> true
1302 ; add_warning(ltsmin_guard_splitting,'Cannot extract guard for:',Name),fail),
1303 Guards \= [],
1304 conjunct_predicates_with_pos_info(Guards,G),
1305 get_texpr_info(Body,BInfo),
1306 NewBody = b(precondition(G,RestBody),subst,[prob_annotation('LTSMIN-GUARD')|BInfo]), % a SELECT would be more appropriate
1307 (debug_mode(off) -> true
1308 ; format('Extracting LTS Min guard for ~w~n',[Name]),translate:print_subst(NewBody),nl).
1309 cleanup_post_with_path(exists(Ids,B),Type,OInfo,exists(Ids,B),Type,NInfo,single/invalidate_used_ids,_Path) :-
1310 delete(OInfo,used_ids(_),NInfo). % the changes done by cleanups, e.g, removing unused predicates can affect used_ids
1311 cleanup_post_with_path(forall(Ids,LHS,RHS),Type,OInfo,forall(Ids,LHS,RHS),Type,NInfo,single/invalidate_used_ids,_Path) :-
1312 delete(OInfo,used_ids(_),NInfo). % ditto
1313 cleanup_post_with_path(OExpr,OType,OInfo,NExpr,NType,NInfo,Mode/Rule,Path) :-
1314 get_preference(optimize_ast,true),
1315 cleanup_post_ne_with_path(OExpr,OType,OInfo,NExpr,NType,NInfo,Mode/Rule,Path).
1316 cleanup_post_with_path(OExpr,OType,OInfo,NExpr,NType,NInfo,Mode/Rule,_Path) :-
1317 ? cleanup_post_essential(OExpr,OType,OInfo,NExpr,NType,NInfo,Mode/Rule).
1318
1319 % delete an assignment from a substitution
1320 delete_assignment(b(assign(LHS,RHS),subst,Info),ID,IDRHS,b(RES,subst,Info)) :-
1321 ? nth1(Pos,LHS,ID,RestLHS),
1322 nth1(Pos,RHS,IDRHS,RestRHS),
1323 (RestLHS = [] -> RES = skip ; RES = assign(RestLHS,RestRHS)).
1324 % TO DO: also deal with parallel and possibly other constructs assign_single_id,...
1325
1326 %unguarded(path_arg(sequence/1,1)). % first argument of sequence is not guarded
1327 ?unguarded(path_arg(X,_)) :- unguarded_aux(X).
1328 unguarded_aux(top_level(_)).
1329 unguarded_aux(operation/4).
1330 unguarded_aux(parallel/1).
1331 unguarded_aux(var/2).
1332 unguarded_aux(let/3).
1333 % what about choice/2 ??
1334
1335 :- load_files(library(system), [when(compile_time), imports([environ/2])]).
1336
1337
1338 % ---------------------
1339
1340 % now the rules which do not need the Path
1341
1342 % first check for a few expressions that never need to be optimised, rewritten:
1343 cleanup_post_essential(E,_,_,_,_,_,_) :- never_transform_or_optimise(E),!,fail.
1344
1345 cleanup_post_essential(Expr,Type,I,Expr,Type,I2,single/remove_erroneous_info_field) :-
1346 \+ ground(I),!,
1347 functor(Expr,F,_N),
1348 add_internal_error('Information field not ground: ',I:F),
1349 I2=[].
1350 cleanup_post_essential(comprehension_set(Ids,E),Type,I,comprehension_set(Ids,E),Type,I,single/sanity_check) :-
1351 get_preference(prob_safe_mode,true),
1352 get_texpr_ids(Ids,UnsortedIds),sort(UnsortedIds,SIds),
1353 \+ same_length(UnsortedIds,SIds),
1354 add_error(cleanup_post,'Identifier clash in comprehension set: ',UnsortedIds),
1355 print(E),nl,
1356 fail.
1357
1358
1359 cleanup_post_essential(lambda(Ids,Pred,Expr),Type,I,
1360 comprehension_set(CompIds,CompPred),Type,NewInfo,multi/remove_lambda) :- !,
1361 unify_types_strict(Type,set(couple(_ArgType,ResType))),
1362 get_unique_id_inside('_lambda_result_',Pred,Expr,ResultId),
1363 def_get_texpr_id(Result,ResultId),
1364 get_texpr_type(Result,ResType),
1365 get_texpr_info(Result,[lambda_result(ResultId)]),
1366 append(Ids,[Result],CompIds),
1367 get_texpr_expr(Equal,equal(Result,Expr)),
1368 get_texpr_type(Equal,pred),
1369 extract_important_info_from_subexpression(Expr,EqInfo), % mark equality with wd condition if Expr has wd condition
1370 ? (member(prob_annotation('SYMBOLIC'),EqInfo)
1371 -> % something like %p.(p : BOOL|%t.(t : NATURAL|t .. t + 7))
1372 (debug_mode(off) -> true
1373 ; write('Marking lambda as symbolic because result is symbolic: '),print_bexpr(Expr),nl),
1374 add_info_if_new(I,prob_annotation('SYMBOLIC'),NewInfo)
1375 ? ; infinite_or_symbolic_domain_for_lambda(Ids,Pred,Kind)
1376 -> % something like %t.(t : NATURAL|t .. t + 7)
1377 (debug_mode(off) -> true
1378 ; get_texpr_ids(Ids,AIds),
1379 format('Marking lambda over ~w as symbolic because the domain is ~w: ',[AIds,Kind]),
1380 print_bexpr(Pred),nl),
1381 add_info_if_new(I,prob_annotation('SYMBOLIC'),NewInfo)
1382 ; NewInfo = I),
1383 get_texpr_info(Equal,[prob_annotation('LAMBDA-EQUALITY')|EqInfo]),
1384 conjunct_predicates_with_pos_info(Pred,Equal,CompPred0),
1385 add_texpr_infos(CompPred0,[prob_annotation('LAMBDA')],CompPred). % checked e.g. in is_converted_lambda_closure
1386 %print_bexpr(b(comprehension_set(CompIds,CompPred),Type,NewInfo)),nl.
1387
1388 cleanup_post_essential(reflexive_closure(Rel),Type,I, UNION,Type,NewInfo,multi/remove_reflexive_closure) :- !,
1389 NewInfo = [was(reflexive_closure)|I],
1390 safe_create_texpr(closure(Rel),Type,I,CL),
1391 UNION = union(b(event_b_identity,Type,IdInfo), CL), % closure(R) = id \/ closure1(R)
1392 (is_infinite_ground_type(Type) -> IdInfo = [prob_annotation('SYMBOLIC')|I] ; IdInfo =I),
1393 (debug_mode(on) -> print('Rewriting closure to: '), print_bexpr(b(UNION,Type,[])),nl ; true).
1394 cleanup_post_essential(evb2_becomes_such(Ids,Pred),subst,I,becomes_such(Ids,Pred2),subst,I,multi/ev2_becomes_such) :-
1395 % we translate a Classical-B becomes_such with id -> id$0, id' -> id
1396 % classical B: Dec = BEGIN level : (level>=0 & level> level$0-5 & level < level$0) END
1397 % Event-B: level'>= 0, level' > level-5 ...
1398 !,
1399 prime_identifiers(Ids,PIds),
1400 maplist(gen_rename,PIds,Ids,RenameList1), % id' -> id
1401 prime_identifiers0(Ids,PIds0),
1402 maplist(gen_rename,Ids,PIds0,RenameList2), % id -> id$0
1403 append(RenameList1,RenameList2,RenameList),
1404 rename_bt(Pred,RenameList,Pred2),
1405 (debug_mode(off) -> true
1406 ; format('Converting Event-B becomes_such: ',[]), print_bexpr(Pred2),nl).
1407 cleanup_post_essential(successor,Type,I,Compset,Type,[was(successor)|I],multi/successor) :- !,
1408 % translation of succ
1409 pred_succ_compset(add,Compset).
1410 cleanup_post_essential(rev(A),string,I,ExtFunCall,string,[was(rev)|I],multi/rev_for_string) :- !,
1411 % translation of rev for STRINGs, this can only occur when allow_sequence_operators_on_strings is true
1412 ExtFunCall = external_function_call('STRING_REV',[A]).
1413 cleanup_post_essential(concat(A,B),string,I,ExtFunCall,string,[was(concat)|I],multi/concat_for_string) :- !,
1414 % translation of concat (^) for STRINGs, can only occur when allow_sequence_operators_on_strings is true
1415 construct_string_append(A,B,ExtFunCall).
1416 cleanup_post_essential(general_concat(A),string,I,ExtFunCall,string,[was(general_concat)|I],multi/concat_for_string) :-
1417 !, % translation of conc for seq(STRING) --> STRING, can only occur when allow_sequence_operators_on_strings is true
1418 ExtFunCall = external_function_call('STRING_CONC',[A]).
1419 cleanup_post_essential(size(A),integer,I,ExtFunCall,integer,[was(A)|I],multi/concat_for_string) :-
1420 get_texpr_type(A,string),!,
1421 % translation of size for STRING, this can only occur when allow_sequence_operators_on_strings is true
1422 ExtFunCall = external_function_call('STRING_LENGTH',[A]).
1423 cleanup_post_essential(predecessor,Type,I,Compset,Type,[was(predecessor)|I],multi/predecessor) :- !,
1424 % translation of pred
1425 pred_succ_compset(minus,Compset).
1426 cleanup_post_essential(becomes_such(Ids1,Pred),subst,I,becomes_such(Ids2,Pred),subst,I,single/becomes_such) :- !,
1427 annotate_becomes_such_vars(Ids1,Pred,Ids2).
1428 cleanup_post_essential(Expr,Type,I,Expr,Type,[contains_wd_condition|I],multi/possibly_undefined) :-
1429 % multi: rule can only be applied once anyway, no need to check
1430 nonmember(contains_wd_condition,I),
1431 % print(' - CHECK WD: '), print_bexpr(Expr),nl, %%
1432 is_possibly_undefined(Expr),!,
1433 %% print('CONTAINS WD: '), print_bexpr(Expr),nl, %%
1434 %(translate:translate_bexpression(Expr,'{min(xunits)}') -> trace ; true),
1435 true.
1436 % if a substitution has a sub-expression that is a substitution with that refers to the original
1437 % value of a variable, we mark this substitution, too.
1438
1439 % If the substitution of an operation contains a while whose invariant contains references x$0
1440 % to the original value of a variable x, we must insert a LET substitution to preserve the original value.
1441 cleanup_post_essential(operation(Id,Results,Args,Body),Type,I,operation(Id,Results,Args,NewBody),Type,I,single/refers_to_old_state_let) :-
1442 get_texpr_info(Body,BodyInfo),
1443 memberchk(refers_to_old_state(References),BodyInfo),!,
1444 create_equalities_for_let(References,Ids,Equalities),
1445 conjunct_predicates_with_pos_info(Equalities,P),
1446 insert_let(Body,Ids,P,NewBody).
1447 cleanup_post_essential(Subst,subst,I,Subst,subst,NI,single/refers_to_old_state) :-
1448 safe_syntaxelement_det(Subst,Subs,_,_,_),
1449 % check if a child contains the refers_to_old_state flag
1450 findall(Reference, (member(Sub,Subs),
1451 get_texpr_info(Sub,SubInfo),
1452 memberchk(refers_to_old_state(References),SubInfo),
1453 member(Reference,References)), ReferedIds),
1454 ReferedIds \= [],
1455 !,
1456 sort(ReferedIds,SortedIds),
1457 NI = [refers_to_old_state(SortedIds)|I].
1458
1459 cleanup_post_essential(let_predicate([],[],TExpr),Type,Iin,Expr,Type,Iout,multi/remove_let_predicate) :- !,
1460 % same as above, just for predicates
1461 get_texpr_expr(TExpr,Expr),
1462 get_texpr_info(TExpr,I),
1463 % The next is done to prevent removing position information (in case of Event-B invariants, theorems,...)
1464 propagate_pos_info_if_useful(I,Iin,Iout).
1465
1466 cleanup_post_essential(OExpr,OType,OInfo,NExpr,NType,NInfo,Mode/Rule) :-
1467 get_preference(optimize_ast,true),
1468 ? cleanup_post(OExpr,OType,OInfo,NExpr,NType,NInfo,Mode/Rule).
1469
1470 % moved these rule below the simplifciation rules above to avoid re-computing used_id infos
1471 cleanup_post_essential(forall(Ids,Lhs,Rhs),pred,IOld,Res,pred,INew,single/forall_used_identifier) :-
1472 reconstruct_forall(Ids,Lhs,Rhs,IOld, b(Res,pred,INew)).
1473 cleanup_post_essential(exists(Ids,P),pred,IOld,exists(Ids,NP),pred,ResInfo,single/exists_used_identifier) :-
1474 inner_predicate_level_optimizations(P,NP),
1475 add_used_identifier_info(Ids,NP,IOld,INew0),
1476 add_used_ids_defined_by_equality(Ids,NP,INew0,INew),
1477 %print('* POST => '),print_bexpr(b(exists(Ids,NP),pred,INew)),nl,
1478 %print(' INFO=> '),print(INew),nl,
1479 % TO DO: also compute which identifiers are worth waiting for; do not wait for res in #x.(x:E & ... & res=min(f(x)))
1480 add_removed_typing_info(INew,ResInfo).
1481 cleanup_post_essential(Construct,Type,I,NewConstruct,Type,I,single/detect_partitions) :-
1482 contains_predicate(Construct,Type,Pred,NewConstruct,NewPred),!, % something like a select or other substitution
1483 predicate_level_optimizations(Pred,NewPred).
1484 cleanup_post_essential(Construct,Type,I,NewConstruct,Type,I,single/detect_partitions2) :-
1485 contains_predicates(Construct,Type,Preds,NewConstruct,NewPreds),!,
1486 maplist(predicate_level_optimizations,Preds,NewPreds) % TO DO: do CSE together (in some cases) !
1487 . %, (Preds=NewPreds -> true ; print('Found partitions: '), translate:print_subst(b(NewConstruct,Type,I)),nl).
1488
1489 construct_inner_forall(Ids,LHS,RHS,OldInfo,Res) :-
1490 delete(OldInfo,used_ids(_),I1), % we construct a changed forall construct; old used_ids info possibly incorrect
1491 reconstruct_forall(Ids,LHS,RHS,I1,Res).
1492 % use when in cleanup_post you construct a forall which will not be at the top-level
1493 % (meaning that the above essential rules will not run)
1494 reconstruct_forall(Ids,LHS,RHS,OldInfo, b(Res,pred,NewInfo)) :-
1495 inner_predicate_level_optimizations(LHS,NLhs),
1496 inner_predicate_level_optimizations(RHS,NRhs),
1497 construct_forall_opt(Ids,NLhs,NRhs,OldInfo, Res,NewInfo).
1498
1499 construct_forall_opt(IDs,NLhs,NRhs,Info, Res,NewInfo) :-
1500 (is_truth(NRhs) ; is_falsity(NLhs)),!,
1501 add_hint_message(remove_useless_assign,'Removing useless universal quantification','',Info),
1502 Res= truth, NewInfo = [was(forall(IDs,NLhs,NRhs))|Info].
1503 % TO DO: is the following rule useful ?: will require adapting test 510 output file
1504 % triggers e.g. for test 1447
1505 %construct_forall_opt([TID],LHS,RHS,Info, Res,NewInfo) :- % !x. (x:SetA => x:SetB) ---> SetA <: SetB
1506 % is_valid_id_member_check(LHS,TID,SetA), is_valid_id_member_check(RHS,TID,SetB),
1507 % !,
1508 % (debug_mode(off) -> true
1509 % ; format('Replacing forall ~w by subset: ',[TID]), print_bexpr(b(subset(SetA,SetB),pred,Info)),nl
1510 % ),
1511 % Res = subset(SetA,SetB), NewInfo = [was(forall)|Info].
1512 construct_forall_opt(Ids,NLhs,NRhs,OldInfo, forall(Ids,NLhs,NRhs),ResInfo) :-
1513 conjunct_predicates([NLhs,NRhs],P),
1514 add_used_identifier_info(Ids,P,OldInfo,Info),
1515 add_removed_typing_info(Info,ResInfo).
1516
1517 add_removed_typing_info(Info,ResInfo) :-
1518 (memberchk(removed_typing,Info) -> ResInfo = Info ; ResInfo = [removed_typing|Info]).
1519
1520 disjoint_ids(Ids1,Ids2) :-
1521 get_texpr_ids(Ids1,I1), sort(I1,SI1),
1522 get_texpr_ids(Ids2,I2), sort(I2,SI2),
1523 ord_disjoint(SI1,SI2).
1524
1525
1526 % translate concat(^) of strings:
1527 construct_string_append(A,B,ExtCall) :-
1528 is_string_conc_or_append(A,List,InfoA), !, % nested concat -> translate to STRING_CONC to enable optimisations
1529 append(List,[B],NewList),
1530 ExtCall = external_function_call('STRING_CONC',[S]),
1531 get_texpr_info(B,IB),merge_info(InfoA,IB,Info),
1532 S = b(sequence_extension(NewList),seq(string),Info).
1533 construct_string_append(A,B,external_function_call('STRING_APPEND',[A,B])).
1534
1535 is_string_conc_or_append(b(external_function_call(F,FArgs),_,Info),Args,Info) :-
1536 (F='STRING_APPEND' -> Args = FArgs
1537 ; F='STRING_CONC',
1538 FArgs = b(sequence_extension(SArgs),_,_)
1539 -> Args = SArgs).
1540
1541 % ---------------------
1542
1543 % non-essential post cleanup rules; only applied when optimize_ast is TRUE
1544
1545 % WITH PATH:
1546
1547 cleanup_post_ne_with_path(member(E,b(image(Rel,SONE),TypeImg,InfoImg)),pred,I,member(Couple,Rel),pred,I,multi/replace_image_by_member,Path) :-
1548 % x : Rel[{One}] => One|->x : Rel
1549 Path \= [path_arg(forall/3,1)|_], % not LHS of a forall
1550 %% do not do this if it is the LHS of a forall: !(aus2).( aus2 : helper[{mm}] => RHS) (as we no longer can apply the optimized set treatment for forall
1551 singleton_set_extension(SONE,One),
1552 %% Rel \= b(reverse(_),_,_), %% TO DO: maybe exclude this; here user maybe wants to explicitly compute image ?
1553 !,
1554 create_couple(One,E,Couple),
1555 (debug_mode(off) -> true
1556 ; print('Member of Image: '),print_bexpr(b(member(E,b(image(Rel,SONE),TypeImg,InfoImg)),pred,I)),nl,
1557 print(' replaced by: '),print_bexpr(b(member(Couple,Rel),pred,I)),nl
1558 ).
1559
1560
1561 % WITHOUT PATH:
1562
1563 cleanup_post(conjunct(b(truth,pred,I1),b(B,pred,I2)),pred,I0,B,pred,NewI,multi/remove_truth_conj1) :- !,
1564 include_important_info_from_removed_pred(I1,I2,I3), % ensure was,... information propagated
1565 add_important_info_from_super_expression(I0,I3,NewI).
1566 cleanup_post(conjunct(b(A,pred,I2),b(truth,pred,I1)),pred,I0,A,pred,NewI,multi/remove_truth_conj2) :- !,
1567 include_important_info_from_removed_pred(I1,I2,I3),
1568 add_important_info_from_super_expression(I0,I3,NewI).
1569 cleanup_post(conjunct(b(falsity,pred,I1),b(_,_,I2)),pred,I0,falsity,pred,NewI,multi/simplify_falsity_conj1) :- !,
1570 include_important_info_from_removed_pred(I2,I1,I3),
1571 add_important_info_from_super_expression(I0,I3,NewI).
1572 cleanup_post(conjunct(LHS,b(falsity,pred,I2)),pred,I0,falsity,pred,NewI,multi/simplify_falsity_conj2) :-
1573 always_well_defined_or_wd_reorderings_allowed(LHS), % we can only improve WD here,
1574 % also checks allow_improving_wd_mode preference
1575 !, % Note: ProB would treat falsity first anyway; so in principle this could be done always for solving
1576 get_texpr_info(LHS,I1),
1577 include_important_info_from_removed_pred(I1,I2,I3),
1578 add_important_info_from_super_expression(I0,I3,NewI).
1579 % we use FInfo: in case it has a was(.) field, e.g., for pretty printing and unsat core generation and unsatCore.groovy test
1580 cleanup_post(conjunct(AA,BB),pred,I,Res,pred,I,multi/modus_ponens) :-
1581 Impl = b(implication(A,B),pred,_),
1582 ((AA,BB) = (Impl,A2) ; (BB,AA) = (Impl,A2)),
1583 same_texpr(A,A2),
1584 % arises e.g., for predicates such as IF x:0..3 THEN y=2 ELSE 1=0 END ; works with simplify_falsity_impl3 rule
1585 % rewrite (A=>B) & A into (A&B)
1586 !,
1587 (debug_mode(off) -> true ; print('Modus Ponens: '),print_bexpr(A), print(' => '), print_bexpr(B),nl),
1588 Res = conjunct(A,B).
1589 %cleanup_post(conjunct(TLHS,P1),pred,_,LHS,pred,Info,multi/duplicate_pred) :-
1590 % % TO DO: implement an efficient version of this; currently very slow e.g. for test 293
1591 % b_interpreter:member_conjunct(P2,TLHS,_),
1592 % same_texpr(P1,P2),
1593 % TLHS = b(LHS,pred,Info),
1594 % print('remove_duplicate: '), print_bexpr(P1),nl.
1595 cleanup_post(conjunct(LHS,b(Comparison1,pred,_)),pred,I0,Result,pred,RInfo,multi/detect_interval1) :-
1596 % X <= UpBound & X >= LowBound <=> X : UpBound .. LowBound (particularly useful when CLPFD FALSE, causes problem with test 1771)
1597 % Note: x>18 & y<1024 & x<20 & y>1020 now works, it is bracketed ((()) & y>1020)
1598 get_preference(use_clpfd_solver,false),
1599 \+ data_validation_mode, % this rule may lead to additional enumerations
1600 get_leq_comparison(Comparison1,X,UpBound),
1601 ? select_conjunct(b(Comparison2,_,_),LHS,Prefix,Suffix),
1602 get_geq_comparison(Comparison2,X2,LowBound),
1603 same_texpr(X,X2),
1604 (always_well_defined_or_disprover_mode(UpBound)
1605 -> true
1606 ; % as we may move valuation earlier, we have to be careful
1607 % we check if Comparison2 is last conjunct; x=7 & x:8..(1/0) raises no WD error in ProB
1608 Suffix=[]
1609 ),
1610 !,
1611 create_interval_member(X,LowBound,UpBound,Member),
1612 append(Prefix,[Member|Suffix],ResultList),
1613 conjunct_predicates(ResultList,TResult),
1614 TResult = b(Result,pred,I1),
1615 add_important_info_from_super_expression(I0,I1,RInfo),
1616 (debug_mode(off) -> true ; print(' Detected interval membership (1): '),print_bexpr(b(Result,pred,RInfo)),nl).
1617 cleanup_post(conjunct(LHS,b(Comparison1,pred,_)),pred,I0,Result,pred,RInfo,multi/detect_interval2) :-
1618 % X >= LowBound & X <= UpBound <=> X : UpBound .. LowBound
1619 get_preference(use_clpfd_solver,false),
1620 \+ data_validation_mode, % this rule may lead to additional enumerations
1621 get_geq_comparison(Comparison1,X,LowBound),
1622 ? select_conjunct(b(Comparison2,_,_),LHS,Prefix,Suffix),
1623 get_leq_comparison(Comparison2,X2,UpBound),
1624 same_texpr(X,X2),
1625 (always_well_defined_or_disprover_mode(LowBound)
1626 -> true
1627 ; % as we may move valuation earlier, we have to be careful
1628 % we check if Comparison2 is last conjunct; x=7 & x:8..(1/0) raises no WD error in ProB
1629 Suffix=[]
1630 ),
1631 !,
1632 create_interval_member(X,LowBound,UpBound,Member),
1633 append(Prefix,[Member|Suffix],ResultList),
1634 conjunct_predicates(ResultList,TResult),
1635 TResult = b(Result,pred,I1),
1636 add_important_info_from_super_expression(I0,I1,RInfo),
1637 (debug_mode(off) -> true ; print(' Detected interval membership (2): '),print_bexpr(b(Result,pred,RInfo)),nl).
1638
1639 cleanup_post(disjunct(b(truth,pred,I1),_),pred,I0,truth,pred,I,multi/simplify_truth_disj1) :- !,
1640 add_important_info_from_super_expression(I0,I1,I).
1641 cleanup_post(disjunct(b(A,pred,I1),b(falsity,pred,_)),pred,I0,A,pred,I,multi/remove_falsity_disj1) :- !,
1642 add_important_info_from_super_expression(I0,I1,I).
1643 cleanup_post(disjunct(b(falsity,pred,_),b(B,pred,I1)),pred,I0,B,pred,I,multi/remove_falsity_disj2) :- !,
1644 add_important_info_from_super_expression(I0,I1,I).
1645 cleanup_post(disjunct(Expr1,b(truth,pred,I1)),pred,I0,truth,pred,I,multi/simplify_truth_disj2) :-
1646 always_well_defined_or_wd_reorderings_allowed(Expr1), !, % we can only improve WD here
1647 add_important_info_from_super_expression(I0,I1,I).
1648 cleanup_post(disjunct(Equality1,Equality2),pred,I,New,pred,I,multi/rewrite_disjunct_to_member1) :-
1649 ? identifier_equality(Equality2,ID,_,Expr2),
1650 always_well_defined_or_disprover_mode(Expr2),
1651 get_texpr_type(Expr2,Type2),
1652 type_contains_no_sets(Type2), % we do not want to generate sets of sets, or worse sets with infinite sets (x=NATURAL1 or ...) which cannot be converted to AVL
1653 ? identifier_equality(Equality1,ID,TID,Expr1),
1654 % Rewrite (ID = Expr1 or ID = Expr2) into ID: {Expr1,Expr2} ; good if FD information can be extracted for ID
1655 % But: can be bad for reification, in particular when set extension cannot be computed fully
1656 % TO DO: also deal with ID : {Values} and more general extraction of more complicated disjuncts
1657 % TO DO: also apply for implication (e.g., ID /= E1 => ID=E2)
1658 !,
1659 construct_set_extension(Expr1,Expr2,SetX),
1660 New=member(TID,SetX),
1661 (debug_mode(off) -> true
1662 ; format('Rewrite disjunct (1) ~w: ',[ID]),print_bexpr(SetX),nl).
1663 cleanup_post(disjunct(LHS1,LHS2),pred,I,New,pred,I,multi/rewrite_disjunct_to_member2) :-
1664 ? id_member_of_set_extension(LHS2,ID,TID1,LExpr2), % also detects equalities
1665 get_texpr_type(TID1,Type),
1666 get_preference(use_clpfd_solver,true),type_contains_fd_index(Type), % merging is potentially useful
1667 maplist(always_well_defined_or_disprover_mode,LExpr2), % TODO: check that merging makes sense, e.g., definite FD values or simple identfiiers
1668 ? id_member_of_set_extension(LHS1,ID,TID,LExpr1),
1669 % Rewrite (ID : {Expr1,...} or ID : {Expr2,...} into ID: {Expr1,Expr2}
1670 l_construct_set_extension(LExpr1,LExpr2,SetX),
1671 New=member(TID,SetX),
1672 (debug_mode(off) -> true
1673 ; format('Rewrite disjunct (2) ~w: ',[ID]),print_bexpr(SetX),nl).
1674 cleanup_post(disjunct(P1,NegP1),pred,Info,truth,pred,Info,multi/tautology_disjunction) :-
1675 % P1 or not(P1) == truth (was created by Rodin for WD)
1676 (get_texpr_expr(NegP1,negation(P1bis)) -> same_texpr(P1,P1bis)
1677 ; get_texpr_expr(P1,negation(NP1)) -> same_texpr(NP1,NegP1)),
1678 (debug_mode(off) -> true
1679 ; format('Detected useless disjunction (tautology): ',[]),print_bexpr(b(disjunct(P1,NegP1),pred,Info)),nl).
1680 cleanup_post(disjunct(CEquality1,CEquality2),pred,IOld,New,pred,INew,multi/factor_common_pred_in_disjunction) :-
1681 % (x=2 & y=3) or (x=2 & y=4) -> x=2 & (y=3 or y=4) to improve constraint propagation
1682 ? factor_disjunct(CEquality1,CEquality2,IOld,New,INew),
1683 (debug_mode(off) -> true
1684 ; format('Factor disjunct: ',[]),print_bexpr(b(New,pred,INew)),nl).
1685 cleanup_post(implication(b(truth,pred,_),b(B,pred,I1)),pred,I0,B,pred,I,multi/remove_truth_impl1) :- !,
1686 add_important_info_from_super_expression(I0,I1,I).
1687 cleanup_post(implication(b(falsity,pred,I1),_),pred,I0,truth,pred,I,multi/simplify_falsity_impl1) :- !,
1688 add_important_info_from_super_expression(I0,I1,I).
1689 cleanup_post(implication(_,b(truth,pred,I1)),pred,I0,truth,pred,I,multi/simplify_truth_impl2) :- !,
1690 add_important_info_from_super_expression(I0,I1,I).
1691 cleanup_post(implication(P,b(falsity,pred,_)),pred,I,NotP,pred,[was(implication)|I],multi/simplify_falsity_impl3) :- !,
1692 create_negation(P,TNotP),
1693 (debug_mode(off) -> true ; print_bexpr(P), print(' => FALSE simplified'),nl),
1694 get_texpr_expr(TNotP,NotP).
1695 % TO DO: is the following rule useful ?:
1696 %cleanup_post(implication(A,b(implication(B,C),pred,_)),pred,IOld,
1697 % implication(AB,C),pred,IOld,single/replace_implication_by_and) :-
1698 % % (A => B => C <==> (A & B) => C
1699 % conjunct_predicates([A,B],AB),
1700 % (debug_mode(off) -> true ; print('Simplifying double implication: '), print_bexpr(b(implication(AB,C),pred,IOld)),nl).
1701 cleanup_post(equivalence(TA,b(B,pred,I1)),pred,I0,B,pred,I,multi/remove_truth_equiv1) :-
1702 is_truth(TA), !,
1703 add_important_info_from_super_expression(I0,I1,I).
1704 cleanup_post(equivalence(b(A,pred,I1),TB),pred,I0,A,pred,I,multi/remove_truth_equiv2) :-
1705 is_truth(TB), !,
1706 add_important_info_from_super_expression(I0,I1,I).
1707 % TO DO: more rules for implication/equivalence to introduce negations (A <=> FALSITY ---> not(A)) ?
1708 % detect certain tautologies/inconsistencies
1709 cleanup_post(lazy_let_pred(_ID,_,b(Sub,pred,I1)),pred,I0,Sub,pred,I,multi/remove_lazy_let_pred) :-
1710 (Sub=truth ; Sub=falsity), !,
1711 add_important_info_from_super_expression(I0,I1,I).
1712 cleanup_post(IFTHENELSE,T,_,Res,T,[was(ifthenelse)|NI],single/remove_if_then_else) :-
1713 explicit_if_then_else(IFTHENELSE,IF,THEN,ELSE),
1714 (is_falsity(IF) -> b(Res,_,NI)=ELSE
1715 ; is_truth(IF) -> b(Res,_,NI)=THEN
1716 ),
1717 (debug_mode(off) -> true
1718 ; print('Simplified IF-THEN-ELSE: '), print_bexpr(IF),nl).
1719 cleanup_post(member(X,B),pred,I,truth,pred,[was(member(X,B))|I],multi/remove_type_member) :-
1720 is_just_type(B),
1721 nonmember(label(_),I), % the user has explicitly labeled this conjunct
1722 !. % print('REMOVE: '),print_bexpr(b(member(X,B),pred,[])),nl, print(I),nl.
1723 %cleanup_post(member(X,SET),pred,I,greater_equal(X,TBound),pred,[was(member(X,SET))|I],multi/remove_type_member) :-
1724 % disabled at the moment: we need to adapt test 1383, 767, 1703, 1003
1725 % is_inf_integer_set_with_lower_bound(SET,Bound),
1726 % Replace x:NATURAL by x>=0 and x:NATURAL1 by x>=1 ; is usually much more efficient
1727 % note : removes virtual timeout in test 290
1728 % !,
1729 % TBound = b(integer(Bound),integer,[]), print('REPLACE: '),print_bexpr(b(member(X,SET),pred,I)),nl, print_bexpr(b(greater_equal(X,TBound),pred,I)),nl.
1730 cleanup_post(not_member(X,B),pred,I,falsity,pred,[was(not_member(X,B))|I],multi/remove_type_not_member) :-
1731 is_just_type(B),
1732 nonmember(label(_),I), % the user has explicitly labeled this conjunct
1733 !.
1734 cleanup_post(member(X,TSet),pred,I,equal(X,One),pred,I,multi/remove_member_one_element_set) :-
1735 singleton_set_extension(TSet,One),
1736 !,
1737 % X:{One} <=> X=One
1738 true. %,print('Introducing equality: '),print_bexpr(X), print(' = '), print_bexpr(One),nl.
1739 cleanup_post(member(X,b(Set,_,_)),pred,I,not_equal(X,One),pred,I,multi/remove_member_setdiff) :-
1740 Set = set_subtraction(MaximalSet,SONE),
1741 singleton_set_extension(SONE,One),
1742 definitely_maximal_set(MaximalSet),
1743 !, % x : INTEGER-{One} <=> x/=One
1744 (debug_mode(off) -> true
1745 ; print('Replacing member of set_subtraction: '), print_bexpr(MaximalSet), print(' - '), print_bexpr(SONE),nl).
1746 cleanup_post(not_member(X,TSet),pred,I,not_equal(X,One),pred,I,multi/remove_member_one_element_set) :-
1747 singleton_set_extension(TSet,One),
1748 !,
1749 % X/:{One} <=> X/=One
1750 true.
1751 cleanup_post(member(E,b(fin_subset(E2),_,_)),pred,I,finite(E),pred,I,multi/introduce_finite) :-
1752 (same_texpr(E,E2); is_just_type(E2)),!. % print(introduce(finite(E))),nl.
1753 cleanup_post(not_member(E,b(fin_subset(E2),_,_)),pred,I,NotFinite,pred,I,multi/introduce_not_finite) :-
1754 (same_texpr(E,E2); is_just_type(E2)),!,
1755 create_negation(b(finite(E),pred,I),TNotP), get_texpr_expr(TNotP,NotFinite).
1756 /* do we want need this rule ?:
1757 clenaup_post(member(b(couple(A,B),couple(TA,TB),IC),ID),pred,I,equal(A,B),pred,I,multi/replace_member_id) :-
1758 is_is_event_b_identity(ID), !.
1759 */
1760 cleanup_post(member(b(couple(A,B),couple(TA,TB),IC),b(reverse(Rel),_,_)),pred,I,member(ICouple,Rel),pred,I,multi/remove_reverse) :- !,
1761 % (A,B) : Rel~ ===> (B,A) : Rel
1762 % can be detrimental for performance when A is known and B is not and Rel is large
1763 \+ data_validation_mode,
1764 (debug_mode(off) -> true ; print('Removed inverse (~): '),print_bexpr(Rel),nl),
1765 ICouple = b(couple(B,A),couple(TB,TA),IC).
1766 cleanup_post(member(LHS,ITE),pred,I,Result,pred,I,multi/member_if_then_else) :-
1767 get_texpr_expr(ITE,if_then_else(IFPRED,THEN,ELSE)),
1768 (definitely_empty_set(ELSE)
1769 -> A=THEN, P = IFPRED
1770 ; definitely_empty_set(THEN)
1771 -> A=ELSE, create_negation(IFPRED,P)
1772 ),
1773 % x: IF P THEN A ELSE {} END --> P & x:A
1774 % x: IF P THEN {} ELSE A END --> not(P) & x:A
1775 % appears in some generated Caval machines
1776 % x: IF a=TRUE THEN {11} ELSE {} END & x>11 can now be solved deterministically
1777 MEM = b(member(LHS,A),pred,I),
1778 conjunct_predicates([P,MEM],TR),
1779 (debug_mode(off) -> true ; print('Replace member of if-then-else by: '),print_bexpr(TR),nl),
1780 get_texpr_expr(TR,Result).
1781 cleanup_post(member(LHS,Comprehension),pred,I,Result,pred,NewInfo,multi/remove_member_comprehension) :-
1782 Comprehension = b(ComprSet,_,_),
1783 is_comprehension_set(ComprSet,[TID],Body),
1784 get_texpr_id(TID,ID),
1785 % LHS:{x|P(x)} ==> P(LHS)
1786 ? replace_id_by_expr_with_count(Body,ID,LHS,TResult,Count),
1787 % rewrite could duplicate LHS: not an issue in CSE mode; optimization relevant in normalize_ast mode
1788 ? is_replace_id_by_expr_ok(LHS,ID,Count,remove_member_comprehension),
1789 !,
1790 % could introduce LET if necessary because ID occurs multiple times (Count>1)
1791 get_texpr_expr(TResult,Result),
1792 get_texpr_info(TResult,I1),
1793 add_important_info_from_super_expression(I,I1,NewInfo),
1794 (debug_mode(off) -> true ; print('Remove element of comprehension_set: '),print_bexpr(Comprehension),nl,
1795 format(' rewriting to (~w): ',[Count]),print_bexpr(TResult),nl).
1796 cleanup_post(not_member(LHS,Comprehension),pred,I,Result,pred,I,multi/remove_not_member_comprehension) :-
1797 Comprehension = b(ComprSet,_,_),
1798 is_comprehension_set(ComprSet,[TID],Body),
1799 get_texpr_id(TID,ID),
1800 % LHS/:{x|P(x)} ==> not(P(LHS))
1801 replace_id_by_expr_with_count(Body,ID,LHS,TResult,Count),
1802 % rewrite could duplicate LHS: not an issue in CSE mode; optimization relevant in normalize_ast mode
1803 ? is_replace_id_by_expr_ok(LHS,ID,Count,remove_not_member_comprehension),
1804 !,
1805 Result = negation(TResult),
1806 (debug_mode(off) -> true ; print('Remove not element of comprehension_set: '),print_bexpr(Comprehension),nl,
1807 format(' rewriting to (~w): not(',[Count]),print_bexpr(TResult),print(')'),nl).
1808 cleanup_post(comprehension_set(Ids,Body),Type,I,NewExpr,Type,I2,Rule) :-
1809 ? cleanup_comprehension_set(Ids,Body,Type,I,NewExpr,I2,Rule),
1810 !.
1811 cleanup_post(subset(A,B),pred,I,truth,pred,[was(subset(A,B))|I],multi/remove_type_subset) :-
1812 is_just_type(B),
1813 nonmember(label(_),I), % the user has explicitly labeled this conjunct
1814 !.
1815 cleanup_post(not_subset(A,B),pred,I,falsity,pred,[was(not_subset(A,B))|I],multi/remove_type_not_subset) :-
1816 is_just_type(B),
1817 nonmember(label(_),I), % the user has explicitly labeled this conjunct
1818 !.
1819 cleanup_post(SUB,pred,I,NewPred,pred,[generated_conjunct|I],multi/replace_subset_by_element) :-
1820 is_subset(SUB,A,B),
1821 is_set_extension(A,List),
1822 !, % for sequence extension we don't need this as the interpreter knows exactly the cardinality of a sequence_extension ?
1823 % applying rule {x1,x2,...} <: B <=> x1:B & x2:B & ...
1824 maplist(gen_member_predicates(B),List,Conjuncts),
1825 conjunct_predicates(Conjuncts,TNewPred),
1826 % print('detected subset-member rule: '),print_bexpr(TNewPred),nl,
1827 get_texpr_expr(TNewPred,NewPred).
1828 cleanup_post(SUB,pred,I,NewPred,pred,[generated_conjunct|I],multi/replace_union_subset) :-
1829 is_subset(SUB,A,B),
1830 % mark conjunct as generated: used e.g. by flatten_conjunct in predicate_evaluator
1831 get_texpr_expr(A,union(_,_)),!,
1832 % applying rule A1 \/ A2 <: B <=> A1 <: B & A2 <: B
1833 % could be detrimental if checking that something is an element of B is expensive
1834 extract_unions(A,As),
1835 findall(Subi,(member(Ai,As),safe_create_texpr(subset(Ai,B),pred,I,Subi)),Conj), % we could try and re-run clean-up ? safe_create_texpr will ensure WD info set
1836 conjunct_predicates(Conj,TNewPred),
1837 get_texpr_expr(TNewPred,NewPred).
1838 cleanup_post(Comp,pred,I,SComp,pred,I,multi/simplify_cse_comparison) :-
1839 % simplify comparison operations; can result in improved constraint propagation
1840 % e.g., ia + CSE1 * 2 > ia + fa <=> CSE1 * 2 > fa for Setlog/prob-ttf/qsee-TransmitMemoryDumpOk21_SP_3.prob
1841 comparison(Comp,A,B,SComp,SA,SB),
1842 simplify_comparison_terms(A,B,SA,SB),!,
1843 (debug_mode(off) -> true
1844 ; print('Simplified: '),print_bexpr(b(Comp,pred,I)),
1845 print(' <=> '),print_bexpr(b(SComp,pred,I)),nl).
1846 cleanup_post(EMPTYSET,T,I,empty_set,T,[was(EMPTYSET)|I],multi/detect_emptyset) :- EMPTYSET \= empty_set,
1847 definitely_empty_set(b(EMPTYSET,T,I)),
1848 (debug_mode(off) -> true
1849 ; print('Detected empty set: '), print_bexpr(b(EMPTYSET,T,I)),nl).
1850 cleanup_post(equal(A,B),pred,I,truth,pred,[was(equal(A,B))|I],multi/remove_equality) :-
1851 same_texpr(A,B),always_well_defined_or_disprover_mode(A),!. % ,print(removed_equal(A,B)),nl.
1852 cleanup_post(equal(A,B),pred,I,equal(A2,B2),pred,I,multi/simplify_equality) :-
1853 simplify_equality(A,B,A2,B2).
1854 cleanup_post(not_equal(A,B),pred,I,not_equal(A2,B2),pred,I,multi/simplify_inequality) :-
1855 simplify_equality(A,B,A2,B2).
1856 cleanup_post(equal(A,B),pred,I,falsity,pred,[was(equal(A,B))|I],multi/remove_equality_false) :-
1857 different_texpr_values(A,B),!. %,print(removed_equal_false(A,B)),nl.
1858 cleanup_post(equal(A,B),pred,I,greater(Low,Up),pred,I,multi/remove_equality) :-
1859 % Low..Up = {} <=> Low>Up % is also handled by constraint solver; but other simplifications can apply here
1860 ? (definitely_empty_set(B), is_interval(A,Low,Up) ;
1861 ? definitely_empty_set(A), is_interval(B,Low,Up)),!,
1862 (debug_mode(off) -> true
1863 ; print('Simplified: '), print_bexpr(b(equal(A,B),pred,I)), print(' <=> '),
1864 print_bexpr(b(greater(Low,Up),pred,I)),nl).
1865 cleanup_post(CardGt0Expr,pred,I,not_equal(X,EmptySet),pred,I,multi/remove_cardgt0) :-
1866 get_geq_comparison(CardGt0Expr,Card,One),
1867 % card(P) > 0 -> P\={} if wd guaranteed; also rewrites card(P) >= 1
1868 Card = b(card(X),integer,_), get_integer(One,1),
1869 finite_set_or_disprover_mode(X), % as we keep X, it is sufficient for X to be finite for the rule to be ok
1870 get_texpr_type(X,TX), get_texpr_info(One,I0),
1871 EmptySet = b(empty_set,TX,I0),!,
1872 (debug_mode(off) -> true ; print('Removed card(.) > 0 for set: '), print_bexpr(X), nl).
1873 cleanup_post(CardEq0Expr,pred,I,equal(X,EmptySet),pred,I,multi/remove_cardeq0) :-
1874 is_equality(b(CardEq0Expr,pred,I),Card,Zero),
1875 % card(P) = 0 -> P={} if wd guaranteed
1876 Card = b(card(X),integer,_), get_integer(Zero,0),
1877 finite_set_or_disprover_mode(X),
1878 get_texpr_type(X,TX), get_texpr_info(Zero,I0),
1879 EmptySet = b(empty_set,TX,I0),!,
1880 (debug_mode(off) -> true ; print('Removed card(.) = 0 for set: '), print_bexpr(X), nl).
1881 cleanup_post(CardLt1Expr,pred,I,equal(X,EmptySet),pred,I,multi/remove_cardlt1) :-
1882 get_leq_comparison(CardLt1Expr,Card,Zero),
1883 % card(P) <= 0 -> P={} if wd guaranteed; TODO: also detect card(P) < 1
1884 Card = b(card(X),integer,_), get_integer(Zero,0),
1885 finite_set_or_disprover_mode(X),
1886 get_texpr_type(X,TX), get_texpr_info(Zero,I0),
1887 EmptySet = b(empty_set,TX,I0),!,
1888 (debug_mode(off) -> true ; print('Removed card(.) <= 0 for set: '), print_bexpr(X), nl).
1889 cleanup_post(member(Card,Natural),pred,I,truth,pred,I,multi/remove_card_natural) :-
1890 % card(P) : NATURAL -> truth if wd guaranteed
1891 Card = b(card(X),integer,_),
1892 is_integer_set(Natural,'NATURAL'),
1893 always_well_defined_or_disprover_mode(Card),
1894 !,
1895 (debug_mode(off) -> true ; print('Removed card(.):NATURAL for set: '), print_bexpr(X), nl).
1896 cleanup_post(not_equal(A,B),pred,I,less_equal(Low,Up),pred,I,multi/remove_equality) :-
1897 % Low..Up \= {} <=> Low<=Up % is also handled by constraint solver; but other simplifications can apply here
1898 ? (definitely_empty_set(B), is_interval(A,Low,Up) ;
1899 definitely_empty_set(A), is_interval(B,Low,Up)),!,
1900 (debug_mode(off) -> true
1901 ; print('Simplified: '), print_bexpr(b(equal(A,B),pred,I)), print(' <=> '),
1902 print_bexpr(b(less_equal(Low,Up),pred,I)),nl).
1903 cleanup_post(equal(A,B),pred,I,equal(A,RLet),pred,I,single/detect_recursion) :-
1904 % "A" should be an identifier
1905 get_texpr_id(A,ID),
1906 % check if some side conditions are fulfilled where the recursion detection can be enabled
1907 recursion_detection_enabled(A,B,I),
1908 % A must be recursively used in B:
1909 ? find_recursive_usage(B,ID),
1910 % TO DO: also find mutual recursion !
1911 debug_println(9,recursion_detected(ID)),
1912 !, % create an recursive_let where the body is annotated to be symbolic
1913 get_texpr_type(B,Type), add_texpr_infos(B,[prob_annotation('SYMBOLIC')],B2),
1914 mark_recursion(B2,ID,B3),
1915 %print(marked_recursion(ID)),nl,
1916 safe_create_texpr(recursive_let(A,B3),Type,RLet).
1917 cleanup_post(recursive_let(TID,TBody),T,_,Body,T,I2,single/remove_recursive_let) :- get_texpr_id(TID,ID),
1918 \+ occurs_in_expr(ID,TBody),
1919 debug_println(19,removing_recursive_let(ID)), % required for test 1225
1920 TBody = b(Body,_,I2).
1921 cleanup_post(equal(A,B),pred,Info1,ResultExpr,pred,Info3,multi/simplify_bool_true_false) :-
1922 % simplify bool(X)=TRUE -> X and bool(X)=FALSE -> not(X)
1923 ( get_texpr_expr(A,convert_bool(X)), get_texpr_boolean(B,BOOLVAL)
1924 ;
1925 get_texpr_boolean(A,BOOLVAL),get_texpr_expr(B,convert_bool(X))
1926 ),
1927 get_texpr_info(X,Info2),
1928 add_important_info_from_super_expression(Info1,Info2,Info3),
1929 (BOOLVAL = boolean_true -> get_texpr_expr(X,ResultExpr) ;
1930 BOOLVAL = boolean_false -> create_negation(X,TNX), get_texpr_expr(TNX,ResultExpr)),
1931 !,
1932 (debug_mode(off) -> true
1933 ; format('Simplifying bool(.)=~w to ',[BOOLVAL]),translate:print_bexpr(b(ResultExpr,pred,Info3)),nl).
1934 %cleanup_post(equal(A,B),pred,Info1,equal(REL,CartProd),pred,Info1,multi/simplify_image) :-
1935 % cannot be applied yet; SETS not precompiled yet !
1936 % A = b(image(REL,SetExt),_,_),
1937 % % REL[{OneEl}] = B ----> REL = {OneEl}*B if OneEl is the only possible value
1938 % % such signature appear in Alloy generated code
1939 % SetExt = b(set_extension([_]),set(global(GlobalSetName)),_),
1940 % %bmachine:b_get_named_machine_set_calc(GlobalSetName,_,[_]),
1941 % b_global_set_cardinality(Type,1), % cannot be called yet; global sets not precompiled
1942 % !,
1943 % get_texpr_type(REL,RelType),
1944 % safe_create_texpr(cartesian_product(SetExt,B),RelType,CartProd),
1945 % format('Translating image for singleton set'), print_bexpr(b(equal(REL,CartProd),pred,[])),nl.
1946 cleanup_post(not_equal(A,B),pred,I,falsity,pred,[was(not_equal(A,B))|I],multi/remove_disequality) :-
1947 same_texpr(A,B),always_well_defined_or_disprover_mode(A),!. % ,print(removed_not_equal(A,B)),nl.
1948 % sometimes one uses & TRUE=TRUE to finish off guards, invariants, ...
1949 % exchange lambda expressions by a comprehension set
1950 % TO DO: also add rule for bool(X)=FALSE -> not(X)
1951 cleanup_post(not_equal(A,B),pred,I,truth,pred,[was(not_equal(A,B))|I],multi/remove_disequality_false) :-
1952 different_texpr_values(A,B),!. % ,print(removed_not_equal_false(A,B)),nl.
1953 cleanup_post(not_equal(A,B),pred,I,NewP,pred,[was(not_equal(A,B))|I],multi/not_disjoint_disequality) :-
1954 /* Set1 /\ Set2 /= {} <===> #(zz).(zz:Set1 & zz:Set2) */
1955 preferences:preference(use_smt_mode,true), /* currently this rewriting makes test 1112 fail; TO DO: investigate */
1956 definitely_empty_set(B),
1957 get_texpr_expr(A,intersection(Set1,Set2)),!,
1958 get_texpr_type(Set1,Set1Type), unify_types_strict(Set1Type,set(T)),
1959 ID = b(identifier('_zzzz_unary'),T,[generated]),
1960 ESet1 = b(member(ID,Set1),pred,[]),
1961 ESet2 = b(member(ID,Set2),pred,[]),
1962 create_exists_opt([ID],[ESet1,ESet2],NewPredicate),
1963 (debug_mode(off) -> true
1964 ; print('Transformed not disjoint disequality: '),print_bexpr(NewPredicate),nl),
1965 get_texpr_expr(NewPredicate,NewP).
1966 cleanup_post(equal(b(intersection(A,B),_,_),Empty),pred,I,not_equal(El1,El2),pred,[was(intersection)|I],multi/detect_not_equal) :-
1967 % {El1} /\ {El2} = {} --> El1 \= El2 (disjoint sets)
1968 singleton_set_extension(A,El1),
1969 singleton_set_extension(B,El2),
1970 definitely_empty_set(Empty).
1971 cleanup_post(equal(b(intersection(A,B),_,_),Empty),pred,I,NewDisequality,pred,[was(intersection)|I],multi/detect_disjoint_set_extensions) :-
1972 % {El1,...} /\ {El2,...} = {} --> El1 \= El2 & .... (disjoint sets)
1973 get_texpr_expr(A,set_extension(Els1)), length(Els1,Len1), Len1 < 20,
1974 get_texpr_expr(B,set_extension(Els2)), length(Els2,Len2), Len2 < 20,
1975 Len1 * Len2 < 100,
1976 definitely_empty_set(Empty),
1977 ? maplist(simple_expression,Els1), % avoid duplication of computation
1978 ? maplist(simple_expression,Els2), % ditto
1979 findall(NotEqual, (member(A1,Els1),member(B1,Els2),safe_create_texpr(not_equal(A1,B1),pred,NotEqual)),
1980 NotEquals),
1981 conjunct_predicates(NotEquals,TRes),
1982 (debug_mode(off) -> true
1983 ; write('Expanding disjoint set constraint: '),translate:print_bexpr(TRes),nl
1984 ),
1985 get_texpr_expr(TRes,NewDisequality).
1986 cleanup_post(greater(A,B),pred,I,Res,pred,[was(greater(A,B))|I],multi/eval_greater) :-
1987 get_integer(A,IA), get_integer(B,IB),
1988 (IA>IB -> Res = truth ; Res=falsity).
1989 cleanup_post(less(A,B),pred,I,Res,pred,[was(less(A,B))|I],multi/eval_less) :-
1990 get_integer(A,IA), get_integer(B,IB),
1991 (IA<IB -> Res = truth ; Res=falsity).
1992 cleanup_post(greater_equal(A,B),pred,I,Res,pred,[was(greater_equal(A,B))|I],multi/eval_greater_equal) :-
1993 get_integer(A,IA), get_integer(B,IB),
1994 (IA >= IB -> Res = truth ; Res=falsity).
1995 cleanup_post(less_equal(A,B),pred,I,Res,pred,[was(less_equal(A,B))|I],multi/eval_less_equal) :-
1996 get_integer(A,IA), get_integer(B,IB),
1997 (IA =< IB -> Res = truth ; Res=falsity).
1998 % TODO: similar things for less_real ?
1999 cleanup_post(CHOOSE,real,I,div_real(A,B),real,I,multi/replace_tla_real_division) :-
2000 is_tla_real_division(CHOOSE,A,B),
2001 % Detect TLA real division defined by Div_1(a, b) == CHOOSE({m|m:REAL & m*b=a})
2002 add_debug_message(ast_cleanup,'Translated TLA+ division to real division: ',b(div_real(A,B),real,I),I).
2003 cleanup_post(negation(A),pred,I,falsity,pred,[was(negation(A))|I],multi/remove_negation_truth) :-
2004 is_truth(A),!. % ,print(negation(A)),nl.
2005 cleanup_post(negation(A),pred,I,truth,pred,[was(negation(A))|I],multi/remove_negation_falsity) :-
2006 is_falsity(A),!. % ,print(negation(A)),nl.
2007 cleanup_post(convert_bool(A),boolean,I,Res,boolean,I,multi/remove_convert_bool) :-
2008 (is_truth(A) -> Res = boolean_true
2009 ; is_falsity(A) -> Res = boolean_false
2010 ; is_equality(A,LHS,BoolTRUE), get_texpr_boolean(BoolTRUE,boolean_true) % bool(LHS=TRUE) --> LHS
2011 -> get_texpr_expr(LHS,Res)
2012 ; A=not_equal(LHS,BoolFALSE), get_texpr_boolean(BoolFALSE,boolean_false) % bool(LHS/=FALSE) --> LHS
2013 -> get_texpr_expr(LHS,Res)
2014 ),!.
2015 cleanup_post(assertion_expression(Cond,_ErrMsg,Expr),_T,I0,BE,TE,IE,multi/remove_assertion_expression) :-
2016 is_truth(Cond),!,
2017 Expr = b(BE,TE,I1),
2018 add_important_info_from_super_expression(I0,I1,IE).
2019 cleanup_post(card(INTERVAL), T, I, Res, T, I, single/card_of_interval) :-
2020 % e.g., card(1..4) -> 4
2021 ? is_interval(INTERVAL, LowerBound, UpperBound),
2022 get_integer(LowerBound, L),
2023 number(L),
2024 get_integer(UpperBound, U),
2025 number(U),
2026 (L > U -> Card = 0 ; Card is 1+(U - L)),
2027 !,
2028 Res = integer(Card).
2029 cleanup_post(member(Empty,TPow),T,I,Res,T,I,single/empty_set_in_pow_subset) :-
2030 definitely_empty_set(Empty), % useful for z3 integration to prevent powerset constraint
2031 TPow = b(POW,_,_),
2032 (POW=pow_subset(_) -> RT=truth
2033 ; POW=fin_subset(_) -> RT=truth
2034 ; POW=pow1_subset(_) -> RT=falsity
2035 ; POW=fin1_subset(_) -> RT=falsity),
2036 always_well_defined_or_disprover_mode(TPow),
2037 !,
2038 Res = RT.
2039 cleanup_post(card(Empty),T,I,Res,T,I,single/card_singleton_set) :-
2040 Empty = b(empty_set,_,_), % useful for z3 integration to prevent cardinality constraint
2041 !,
2042 Res = integer(0).
2043 cleanup_post(card(SONE),T,I,Res,T,I,single/card_singleton_set) :-
2044 singleton_set_extension(SONE,One), % card({One}) = 1 ; useful for alloy2b
2045 always_well_defined_or_disprover_mode(One),
2046 !,
2047 Res = integer(1).
2048 cleanup_post(cartesian_product(A,B),T,I,Res,T,I,single/cartesian_product_to_pair) :-
2049 singleton_set_extension(A,El1),
2050 singleton_set_extension(B,El2), % {A}*{B} -> {A|->B} ; happens in Alloy translations a lot
2051 !,
2052 get_texpr_type(El1,T1), get_texpr_type(El2,T2),
2053 safe_create_texpr(couple(El1,El2),couple(T1,T2),Pair),
2054 Res = set_extension([Pair]).
2055 cleanup_post(image(Fun,Empty),T,I,empty_set,T,I,multi/image_empty_optimisation) :-
2056 definitely_empty_set(Empty),
2057 always_well_defined_or_wd_improvements_allowed(Fun),
2058 !,
2059 (debug_mode(off) -> true
2060 ; add_message(ast_cleanup,'Removing unnecessary image of empty set: ',Fun,I)).
2061 cleanup_post(union(A,B),T,I,Res,T,[add_element_to_set|I],multi/add_element_to_set) :- % multi: cycle check done in info field
2062 ? \+ member(add_element_to_set,I),
2063 ( singleton_set_extension(B,_El) -> Res = union(A,B)
2064 ; singleton_set_extension(A,_El) -> Res = union(B,A)),
2065 !. %,print(detected_add_singleton_element(_El)),nl.
2066 cleanup_post(union(A,B),T,I,Res,T,I,multi/union_empty_set) :-
2067 ( definitely_empty_set(A) -> get_texpr_expr(B,Res) % {} \/ B = B
2068 ; definitely_empty_set(B) -> get_texpr_expr(A,Res) % A \/ {} = A
2069 ),
2070 !.
2071 cleanup_post(intersection(A,B),T,I,empty_set,T,I,multi/intersection_empty_set) :-
2072 ( definitely_empty_set(A) -> true % A /\ {} = {}
2073 ; definitely_empty_set(B) -> true % {} /\ B = {}
2074 ),
2075 !.
2076 cleanup_post(set_subtraction(A,B),T,I,Res,T,I,multi/intersection_empty_set) :-
2077 ( definitely_empty_set(A) -> Res=empty_set % {} - B = {}
2078 ; definitely_empty_set(B) -> get_texpr_expr(A,Res) % A - {} = A
2079 ),
2080 !.
2081 cleanup_post(general_union(SetExt),Type,I0,Res,Type,Info,multi/general_union_set_extension) :- % union_generalized
2082 % union({a,b,c,...}) = a \/ b \/ c ...
2083 SetExt = b(set_extension(LIST),_,I1),
2084 add_important_info_from_super_expression(I0,I1,Info),
2085 % no need to apply rule if already transformed into avl in cleanup_pre, hence we do not call is_set_extension
2086 construct_union_from_list(LIST,Type,Info,TRes),
2087 !,
2088 (debug_mode(on) -> print('translated_general_union: '), print_bexpr(TRes),nl ; true),
2089 get_texpr_expr(TRes,Res).
2090 cleanup_post(general_intersection(SetExt),Type,I0,Res,Type,Info,multi/general_inter_set_extension) :- % inter_generalized
2091 % inter({a,b,c,...}) = a /\ b /\ c ...
2092 SetExt = b(set_extension(LIST),_,I1),
2093 add_important_info_from_super_expression(I0,I1,Info),
2094 % no need to apply rule if already transformed into avl in cleanup_pre, hence we do not call is_set_extension
2095 construct_inter_from_list(LIST,Type,Info,TRes),
2096 !,
2097 (debug_mode(on) -> print('translated_general_intersection: '), print_bexpr(TRes),nl ; true),
2098 get_texpr_expr(TRes,Res).
2099 cleanup_post(SUB,pred,I0,FORALL,pred,FInfo,multi/general_union_subset) :-
2100 is_subset(SUB,UNION,T),
2101 % union(S) <: T ===> !x.(x:S => x <: T)
2102 % currently: subsets of T may be generated, but it does not propagate well to S
2103 UNION = b(general_union(S),_,_),
2104 !,
2105 get_unique_id_inside('_zzzz_unary',S,T,ID),
2106 get_texpr_type(S,SType), is_set_type(SType,IDType),
2107 TID = b(identifier(ID),IDType,[generated]),
2108 safe_create_texpr(member(TID,S),pred,LHS),
2109 safe_create_texpr(subset(TID,T),pred,RHS),
2110 create_implication(LHS,RHS,NewForallBody),
2111 create_forall([TID],NewForallBody,TFORALL),
2112 TFORALL = b(FORALL,pred,I1),
2113 add_important_info_from_super_expression(I0,I1,FInfo),
2114 % see test 1854, and ProZ ROZ/model.tex
2115 (debug_mode(on) -> print('translated_general_union subset: '), print_bexpr(TFORALL),nl ; true).
2116 cleanup_post(size(Seq),integer,Info,Res,integer,Info,multi/size_append) :-
2117 get_texpr_expr(Seq,concat(A,B)),
2118 % size(A^B) = size(A)+size(B) useful e.g. for test 1306
2119 !,
2120 Res = add(b(size(A),integer,Info),b(size(B),integer,Info)).
2121 cleanup_post(concat(A,B),Type,I0,Seq,Type,[was(concat)|NewInfo],multi/concat_empty) :-
2122 ( definitely_empty_set(A) -> b(Seq,_,I1)=B
2123 ; definitely_empty_set(B) -> b(Seq,_,I1)=A
2124 ),!,
2125 add_important_info_from_super_expression(I0,I1,NewInfo).
2126 cleanup_post(concat(A,B),Type,I0,Seq,Type,[was(concat)|I0],multi/concat_singleton_seq) :-
2127 ( is_singleton_sequence(B,Element) -> Seq = insert_tail(A,Element)
2128 ; is_singleton_sequence(A,Element) -> Seq = insert_front(Element,B)
2129 ),!,
2130 debug_format(19,'Concat with singleton sequence detected~n',[]).
2131 cleanup_post(E,integer,I,Res,integer,[was(Operator)|I],multi/constant_expression) :-
2132 pre_compute_static_int_expression(E,Result),!,
2133 functor(E,Operator,_),
2134 % format('Precomputed: ~w for ',[Result]), translate:print_bexpr(b(E,integer,[])),nl,
2135 Res = integer(Result).
2136 cleanup_post(min(Interval),integer,I0,Res,integer,Info,multi/eval_min_interval) :-
2137 is_interval_or_singleton(Interval,Low,Up),
2138 get_integer(Low,L), number(L),
2139 get_integer(Up,U), number(U), L =< U, % non-empty interval
2140 debug_println(5,simplified_min_interval(L,U,L)),
2141 Res = integer(L), get_texpr_info(Low,I1),
2142 add_important_info_from_super_expression(I0,I1,Info).
2143 cleanup_post(max(Interval),integer,I0,Res,integer,Info,multi/eval_max_interval) :-
2144 is_interval_or_singleton(Interval,Low,Up),
2145 get_integer(Low,L), number(L),
2146 get_integer(Up,U), number(U), L =< U, % non-empty interval
2147 debug_println(5,simplified_max_interval(L,U,U)),
2148 Res = integer(U), get_texpr_info(Low,I1),
2149 add_important_info_from_super_expression(I0,I1,Info).
2150 cleanup_post(first(Seq),Type,I0,Res,Type,Info,multi/first_seq_extension) :-
2151 is_sequence_extension(Seq,List), List = [First|Rest],
2152 (Rest == [] -> true ; preferences:get_preference(disprover_mode,true)), % we may remove WD issue otherwise (TO DO: check if Rest contains any problematic elements)
2153 !,
2154 First = b(Res,Type,I1),
2155 add_important_info_from_super_expression(I0,I1,Info).
2156 cleanup_post(last(Seq),Type,I0,Res,Type,Info,multi/first_seq_extension) :-
2157 is_sequence_extension(Seq,List), List = [First|Rest],
2158 (Rest == [] -> true ; preferences:get_preference(disprover_mode,true)), % we may remove WD issue otherwise (TO DO: check if list contains any problematic elements)
2159 !,
2160 last([First|Rest],b(Res,Type,I1)),
2161 add_important_info_from_super_expression(I0,I1,Info).
2162 cleanup_post(function(Fun,Arg),Type,Info,New,Type,NewInfo,Rule) :-
2163 ? cleanup_post_function(Fun,Arg,Type,Info,New,NewInfo,Rule).
2164 cleanup_post(range(SETC),Type,I, comprehension_set(RangeIds2,NewCompPred),Type,I,single/range_setcompr) :-
2165 % translate ran({x1,...xn|P}) into {xn| #(x1,...).(P)} ; particularly interesting if x1... contains large datavalues (e.g., C_02_001.mch from test 1131)
2166 get_texpr_expr(SETC,comprehension_set(CompIds,CompPred)),
2167 get_domain_range_ids(CompIds,DomainIds,RangeIds), % print(range(CompIds,DomainIds,RangeIds)),nl,
2168 %\+((member(ID,RangeIds),get_texpr_id(ID,'_lambda_result_'))), % for test 612; maybe disable optimisation if memory consumption of variables small
2169 !, % TO DO: also detect patterns such as dom(dom( or ran(ran( ... [Done ??]
2170 ? rename_lambda_result_id(RangeIds,CompPred,RangeIds2,CompPred1),
2171 rename_lambda_result_id(DomainIds,CompPred1,DomainIds2,CompPred2),
2172 create_outer_exists_for_dom_range(DomainIds2,CompPred2,NewCompPred), % will mark the exists; so that during expansion we will treat it differently for enumeration
2173 (debug_mode(off) -> true
2174 ; print('Encode range as existential quantification: '), print_bexpr(NewCompPred),nl).
2175 cleanup_post(domain(SETC),Type,I, comprehension_set(DomainIds2,NewCompPred),Type,I,single/domain_setcompr) :-
2176 % translate dom({x1,...xn|P}) into {x1,..| #(xn).(P)} ; particularly interesting if xn contains large datavalues
2177 % used to fail test 306 ; fixed by allow_to_lift_exists annotation
2178 \+ data_validation_mode, % sometimes this optimisation is counter-productive for data_validation, problem: test 1945
2179 get_texpr_expr(SETC,comprehension_set(CompIds,CompPred)),
2180 get_domain_range_ids(CompIds,DomainIds,RangeIds), % print(domain(CompIds,DomainIds,RangeIds)),nl,
2181 % \+ (member(ID,CompIds),get_texpr_id(ID,'_lambda_result_')),
2182 % WE HAVE TO BE CAREFUL if xn = LAMBDA_RESULT ; TO DO rename like above for range
2183 % example from test 292: rel(fnc({x,y|x:1..10 & y:1..x})) = {x,y|x:1..10 & y:1..x}
2184 %\+ data_validation_mode, % test 1945 fails with WD errors if we disable this rule
2185 !,
2186 % TO DO: detect when closure is lambda; e.g., for e.g. dom(pred) = INTEGER in test 292 : split(CompIds,Args,Types), closures:is_lambda_value_domain_closure(Args,Types,B, DomainValue, _),; currently create_exists_opt deals with most of this
2187 rename_lambda_result_id(DomainIds,CompPred,DomainIds2,CompPred1),
2188 rename_lambda_result_id(RangeIds,CompPred1,RangeIds2,CompPred2),
2189 create_outer_exists_for_dom_range(RangeIds2,CompPred2,NewCompPred),
2190 (debug_mode(off) -> true
2191 ; get_texpr_ids(DomainIds,DIS), get_texpr_ids(RangeIds,RIS),
2192 ajoin(['Encode domain over ',DIS,' as existential quantification over ',RIS,' : '],Msg),
2193 add_message(ast_cleanup,Msg,NewCompPred,I)).
2194 cleanup_post(domain(SETC),Type,I, comprehension_set(DomainIds,RestPred),Type,I,single/domain_setcompr) :-
2195 % translate dom({x1,...xn|P & xn=E}) into {x1,..| P} ; particularly interesting if xn contains large datavalues
2196 get_texpr_expr(SETC,comprehension_set(CompIds,CompPred)),
2197 get_domain_range_ids(CompIds,DomainIds,RangeIds), % print(domain(CompIds,DomainIds,RangeIds)),nl,
2198 ? \+ (member(ID,CompIds),get_texpr_id(ID,'_lambda_result_')),
2199 conjunction_to_list(CompPred,Preds),
2200 RangeIds = [TId],
2201 get_sorted_ids(RangeIds,Blacklist),
2202 select_equality(TId,Preds,Blacklist,_Eq,_Expr,RestPreds,_,check_well_definedness), % We could do check_well_definedness only if preference set
2203 conjunct_predicates_with_pos_info(RestPreds,RestPred),
2204 not_occurs_in_predicate(Blacklist,RestPred),
2205 !,
2206 % TO DO: use create_optimized exists; also treat inner existential quantification and merge
2207 (debug_mode(off) -> true
2208 ; write('Encode domain of lambda abstraction: '),print_bexpr(RestPred),nl).
2209 cleanup_post(precondition(TP,TS),subst,I0,S,subst,Info,multi/remove_triv_precondition) :-
2210 % remove trivial preconditions
2211 get_texpr_expr(TP,truth),!,
2212 get_texpr_expr(TS,S),get_texpr_info(TS,I1),
2213 add_important_info_from_super_expression(I0,I1,Info).
2214 cleanup_post(external_function_call('ENUM',[TA]),T,I,A,T,[prob_annotation('ENUM')|I],single/process_ENUM) :-
2215 (debug_mode(on) -> format(' Processing ENUM (~w): ',[T]),translate:print_bexpr(TA),nl ; true),
2216 % TO DO: do not process in DEFINITION of ENUM in LibraryProB.def
2217 get_texpr_expr(TA,A).
2218 cleanup_post(external_function_call('FORCE',[TA]),T,I,external_function_call('FORCE',[TA2]),T,I,single/process_FORCE) :-
2219 mark_comprehension_set_with(TA,'FORCE',TA2), % could be sufficient on its own if TA is a comprehension set
2220 % but we keep the call to FORCE, in case TA is re-written or more complex
2221 (debug_mode(off) -> true
2222 ; format(' Processing FORCE: ',[]),translate:print_bexpr(TA2),nl).
2223 cleanup_post(comprehension_set(TIds,Body),T,I1,comprehension_set(TIds,Body2),T,I1,single/detect_lambda_result_auto) :-
2224 get_texpr_info(Body,BI),
2225 (TIds=[_,_,_|_] % check if at least three ids
2226 -> true % for example useful here: {x,y,v| x:INTEGER & y:INTEGER & #z.(z=x+1 & x = y*y & v=z*z & y:1..10)} it could be useful to detect x as DO_NOT_ENUMERATE; currently we only enable this analysis for four ids at least
2227 ; nonmember(prob_annotation('LAMBDA'),BI) % it is a lambda with one argument, no use to do analysis
2228 ),
2229 perform_do_not_enumerate_analysis(TIds,Body,'SET COMPREHENSION',I1,Body2).
2230 cleanup_post(comprehension_set(Ids1,E1),T,I,comprehension_set(Ids2,E2),T,I,multi/detect_lambda_result_user_ann) :-
2231 get_texpr_expr(DNE,external_pred_call('DO_NOT_ENUMERATE',[TID])),
2232 get_texpr_id(TID,ID),
2233 ? member_in_conjunction(DNE,E1),
2234 NewInfo = prob_annotation('DO_NOT_ENUMERATE'(ID)), % similar to lambda_result
2235 E1 = b(PRED,pred,I1),
2236 nonmember(NewInfo,I1),
2237 get_texpr_id(TID,ID),
2238 ? nth1(Pos,Ids1,TID1,Rest),
2239 add_texpr_infos(TID1,[NewInfo],TID2),
2240 nth1(Pos,Ids2,TID2,Rest),
2241 add_message(detect_lambda_result,'Annotating comprehension set identifier with DO_NOT_ENUMERATE: ',ID,I1),
2242 E2 = b(PRED,pred,[NewInfo|I1]).
2243 cleanup_post(record_field(b(rec(Fields),TR,IR),Field),T,I,FieldVal,T,I, single/remove_field_access) :-
2244 always_well_defined_or_disprover_mode(b(rec(Fields),TR,IR)),
2245 ? member(field(Field,TFieldVal),Fields),!,
2246 (debug_mode(off) -> true ; add_message(remove_field_access,'Remove static field access: ',Field,I)), % cf test 1294
2247 get_texpr_expr(TFieldVal,FieldVal).
2248 cleanup_post(sequence([S1,b(sequence(S2),subst,_)]),subst,I,sequence([S1|S2]),subst,I, single/flatten_sequence2) :-
2249 debug_println(9,flatten_sequence2). % do we need something for longer sequences?
2250 cleanup_post(sequence([b(sequence(S1),subst,_)|S2]),subst,I,sequence(NewSeq),subst,I, single/flatten_sequence1) :-
2251 append(S1,S2,NewSeq),
2252 % avoid maybe calling filter_useless_subst_in_sequence again
2253 debug_println(9,flatten_sequence1).
2254 cleanup_post(sequence(S1),subst,I,sequence(S2),subst,I, single/remove_useless_subst_in_seuence) :-
2255 get_preference(useless_code_elimination,true),
2256 filter_useless_subst_in_sequence(S1,Change,S2), debug_println(filter_sequence(9,Change)).
2257 cleanup_post(sequence(Statements),subst,I,Result,subst,I, single/sequence_to_multi_assign) :-
2258 % merge sequence of assignments if possible
2259 merge_assignments(Statements,Merge,New), Merge==merged,
2260 construct_sequence(New,Result).
2261 % nl,print('Merged: '),translate:print_subst(b(Result,subst,I)),nl,nl.
2262 cleanup_post(parallel(Statements),subst,I,Result,subst,I, single/parallel_to_multi_assign) :-
2263 % this merges multiple assignments into a single one: advantage: only one waitflag set up
2264 % should probably not be done in INITIALISATION
2265 % print(parallel(Statements)),nl,trace,
2266 extract_assignments(Statements,LHS,RHS,Rest,Nr), % print(extracted(Nr,LHS)),nl,
2267 Nr>1,!,
2268 (debug_mode(on) ->
2269 print('Parallel to Assignment: '), translate:print_subst(b(parallel(Statements),subst,I)),nl
2270 ; true),
2271 (Rest == [] -> Result = assign(LHS,RHS)
2272 ; Result = parallel([b(assign(LHS,RHS),subst,[])|Rest])).
2273 %translate:print_subst(b(Result,subst,I)),nl.
2274 cleanup_post(select([CHOICE|Rest]),subst,I0,S,subst,Info,single/remove_select) :-
2275 Rest = [], % SELECT can have multiple true branches
2276 CHOICE=b(select_when(TRUTH,Subst),subst,_),
2277 is_truth(TRUTH),!,
2278 debug_println(19,'Removing useless SELECT'),
2279 get_texpr_expr(Subst,S),get_texpr_info(Subst,I1),
2280 add_hint_message(remove_select,'Removing useless SELECT','',I1),
2281 add_important_info_from_super_expression(I0,I1,Info).
2282 cleanup_post(select([CHOICE|Rest],_ELSE),subst,OldInfo,Res,subst,I,single/remove_select_else) :-
2283 CHOICE=b(select_when(TRUTH,Subst),subst,_),
2284 is_truth(TRUTH),!,
2285 (Rest = [] % completely useless SELECT
2286 -> add_hint_message(remove_select_else,'Removing useless SELECT','',OldInfo),
2287 get_texpr_expr(Subst,Res),get_texpr_info(Subst,I1),
2288 add_important_info_from_super_expression(OldInfo,I1,I)
2289 ; add_hint_message(remove_select_else,'Removing useless SELECT ELSE branch','',OldInfo),
2290 Res = select([CHOICE|Rest]), I=OldInfo).
2291 cleanup_post(let_expression([],[],TExpr),Type,I0,Expr,Type,I,multi/remove_let_expression) :- !,
2292 % remove trivial let expressions without any introduced identifiers
2293 % this rule makes only sense in combination with the next rule which removes
2294 % simple let identifiers
2295 get_texpr_expr(TExpr,Expr),
2296 get_texpr_info(TExpr,I1),
2297 add_important_info_from_super_expression(I0,I1,I).
2298 cleanup_post(let([],Pred,TExpr),Type,I0,Expr,Type,I,multi/remove_let) :- is_truth(Pred),!,
2299 % remove trivial let expressions without any introduced identifiers
2300 % this rule makes only sense in combination with the next rule which removes
2301 % simple let identifiers
2302 get_texpr_expr(TExpr,Expr),
2303 get_texpr_info(TExpr,I1),
2304 add_important_info_from_super_expression(I0,I1,I).
2305 cleanup_post(let_expression(TIds,Exprs,Expr),Type,I,
2306 let_expression(NIds,NExprs,NExpr),Type,I,multi/remove_let_expression2) :-
2307 ? simplify_let(TIds,Exprs,Expr,NIds,NExprs,NExpr),!,
2308 %format('~n Simplified Let ~w --> ~w~n',[TIds,NIds]),
2309 true.
2310 cleanup_post(let_predicate(TIds,Exprs,Body),Type,I,
2311 let_predicate(NIds,NExprs,NBody),Type,I,multi/remove_let_predicate2) :-
2312 ? simplify_let(TIds,Exprs,Body,NIds,NExprs,NBody),!,
2313 %format('~n Simplified Let ~w --> ~w~n',[TIds,NIds]),
2314 (is_truth(NBody), NIds \=[]
2315 -> add_debug_message(b_ast_cleanup,'Useless LET predicate: ',Body,I) % not removed due to WD ?
2316 ; true). % if NIds = [] then we will remove it in cleanup_post_essential
2317 cleanup_post(let_predicate(TIds,Exprs,Body),Type,I,
2318 NewExpr,Type,NewI,single/useless_let_message_or_removal) :-
2319 is_truth(Body),
2320 nonmember(useless_let,I),
2321 get_texpr_ids(TIds,Ids),
2322 TE=b(let_predicate(TIds,Exprs,Body),Type,I),
2323 (always_well_defined_or_wd_improvements_allowed(TE)
2324 -> NewExpr = truth, delete(I,contains_wd_condition,NewI),
2325 (always_well_defined_or_disprover_mode(TE)
2326 -> true
2327 ; TIds=[TID1|_],
2328 add_message(b_ast_cleanup,'Removing useless existentially quantified variables: ',Ids,TID1)
2329 )
2330 ; NewExpr = let_predicate(TIds,Exprs,Body), NewI=[useless_let|I],
2331 not_generated_exists_paras(TIds),
2332 % otherwise this was generated programmatically, e.g., in get_operation_enabling_condition, see test 625
2333 (nonmember(allow_to_lift_exists,I) -> true % ditto, e.g., by create_outer_exists_for_dom_range, see test 1945
2334 ; get_preference(data_validation_mode,true)),
2335 add_message(b_ast_cleanup,'Useless existentially quantified variables: ',Ids,TIds)
2336 ).
2337 % was disabled because simplify_let_subst also replaced in RHS of assignments
2338 % but now we check that a LET/ANY variable cannot be assigned to statically
2339 % so it should be safe now to replace simple equalities:
2340 cleanup_post(let(Ids,Pred,Subst),Type,I,
2341 let(NIds,NPred,NSubst),Type,I,multi/remove_let_subst2) :-
2342 simplify_let_subst(Ids,Pred,Subst,NIds,NPred,NSubst),! ,
2343 true. % translate:print_subst(b(let(NIds,NPred,NSubst),subst,[])),nl.
2344
2345
2346 cleanup_post(forall([ID],LHS,RHS),pred,IOld,Res,pred,IOld,single/expand_forall_set_extension) :-
2347 % expand !x.(x:{a,b,...} => RHS) into conjunction
2348 % can be useful e.g. for KODKOD when we pick an element from a set of sets
2349 \+ preferences:has_default_value(use_solver_on_load), % prob, used to be only enabled in Kodkod mode
2350 % TO DO: enable always; but maybe check that set_extension can be computed (which eval_set_extension will do) to avoid duplicating checks (!y.(y:{v,w} => expensive_pred) + what if v=w
2351 nonmember(do_not_optimize_away,IOld),
2352 get_texpr_expr(LHS,member(ID2,Set)),
2353 same_texpr(ID,ID2),
2354 is_set_extension(Set,SList),
2355 get_texpr_id(ID,AID),
2356 debug_format(19,'Expanding forall ~w ',[AID]),
2357 findall(C, (member(SEL,SList),replace_id_by_expr(RHS,AID,SEL,C)),Conjuncts),
2358 conjunct_predicates_with_pos_info(Conjuncts,ExpandedForAll),
2359 (silent_mode(on) -> true ; print_bexpr(ExpandedForAll),nl),
2360 get_texpr_expr(ExpandedForAll,Res).
2361 cleanup_post(forall(Ids1,LHS,RHS),pred,IOld,
2362 forall(Ids,NewLHS,NewRHS),pred,INew,multi/merge_forall) :-
2363 is_truth(LHS),
2364 RHS = b(forall(Ids2,NewLHS,NewRHS),pred,_),
2365 %((member(b(identifier(_),Type,_),Ids1), is_infinite_ground_type(Type)) -> true), % could be useful for tests 1441, 1447 ??
2366 (disjoint_ids(Ids1,Ids2)
2367 -> append(Ids1,Ids2,Ids),
2368 % !x.(truth => !y.(P=>Q) <==> !(x,y).(P=>Q)
2369 (debug_mode(off) -> true ; format('Merging forall ~w: ',[Ids]), print_bexpr(NewLHS),nl),
2370 add_removed_typing_info(IOld,INew)
2371 ; \+ preferences:get_preference(disprover_mode,true),
2372 translate:translate_bexpression(b(forall(Ids1,LHS,RHS),pred,IOld),PS),
2373 add_warning(b_ast_cleanup,'Variable clash in nested universal quantification: ',PS,IOld),
2374 fail
2375 ).
2376 cleanup_post(forall(Ids,LHS,RHS),pred,IOld,
2377 implication(Outer,FORALL),pred,IOld,single/detect_global_preds_forall1) :-
2378 % !x.(P(x) & Q => R(x) <==> Q => !x.(P(x) => R(x))
2379 % TO DO: maybe we should not lift things like printf, ... ?
2380 bsyntaxtree:detect_global_predicates(Ids,LHS,Outer,Inner),
2381 (debug_mode(off) -> true ; format('Lifting predicate (lhs) of forall ~w: ',[Ids]), print_bexpr(Outer),nl),
2382 construct_inner_forall(Ids,Inner,RHS,IOld,FORALL).
2383 % TO DO: implement similar lifting rules for exists(Ids,P)
2384 cleanup_post(forall(Ids,LHS,RHS),pred,IOld,
2385 conjunct(Outer,FORALL),pred,IOld,single/detect_global_preds_forall2) :-
2386 is_truth(LHS),
2387 % !x.(truth => Q & R(x) <==> Q & !x.(truth => R(x))
2388 bsyntaxtree:detect_global_predicates(Ids,RHS,Outer,Inner),
2389 (debug_mode(off) -> true ; format('Lifting predicate (rhs &) of forall ~w: ',[Ids]), print_bexpr(Outer),nl),
2390 construct_inner_forall(Ids,LHS,Inner,IOld, FORALL). % print_bexpr(FORALL),nl,nl.
2391 cleanup_post(forall(Ids,LHS,RHS),pred,IOld,
2392 implication(Outer,FORALL),pred,IOld,single/detect_global_preds_forall3) :-
2393 is_truth(LHS),
2394 RHS = b(implication(RHS1,RHS2),pred,_),
2395 % !x.(truth => (Q & R(x) => S(x)) <==> Q => !x.(truth => R(x) => S(x))
2396 bsyntaxtree:detect_global_predicates(Ids,RHS1,Outer,Inner),
2397 create_implication(Inner,RHS2,NewRHS),
2398 (debug_mode(off) -> true ; format('Lifting predicate (rhs =>) of forall ~w: ',[Ids]), print_bexpr(Outer),nl),
2399 construct_inner_forall(Ids,LHS,NewRHS,IOld, FORALL).
2400 cleanup_post(forall([TID1,TID2|OTHER],LHS,RHS),pred,IOld,
2401 forall([TID1,TID2|OTHER],NewLHS,RHS),pred,[prob_symmetry(ID1,ID2)|IOld],single/symmetry_detection) :-
2402 % DETECT Symmetries such as !(x,y).(x /= y => x=TRUE or y=TRUE)
2403 % !(x2,y).(x2 /= y & x2:s & y:s => x2=aa or y=aa)
2404 % f:1..n --> 1..(n-1) & !(x,y).(x/=y &x:dom(f) & y:1..n => f(x) /= f(y)) & n=9 (runtime 1 sec -> 0.78 sec)
2405 get_texpr_type(TID1,T), get_texpr_type(TID2,T),
2406 \+ preferences:get_preference(use_solver_on_load,kodkod), % e.g., Kodkod cannot properly deal with LEQ_SYM_BREAK, treats it like truth
2407 preferences:get_preference(use_static_symmetry_detection,true),
2408 sym_break_supported_type(T), % LEQ_SYM_BREAK not yet fully functional with SET types; TO DO: fix
2409 get_texpr_id(TID1,ID1), get_texpr_id(TID2,ID2),
2410 nonmember(prob_symmetry(ID1,ID2),IOld),
2411 ? rename_bt(LHS,[rename(ID1,ID2),rename(ID2,ID1)],LHS2),
2412 same_norm_texpr(LHS,LHS2),
2413 rename_bt(RHS,[rename(ID1,ID2),rename(ID2,ID1)],RHS2),
2414 same_norm_texpr(RHS,RHS2),
2415 construct_sym_break(T,TID1,TID2,LHS,SYMBREAK),
2416 conjunct_predicates_with_pos_info(LHS,SYMBREAK,NewLHS),
2417 (debug_mode(off) -> true
2418 ; format('SYMMETRY BREAKING FORALL: !(~w,~w).(',[ID1,ID2]),print_bexpr(NewLHS),
2419 print(' => '), print_bexpr(RHS),print(')'),nl).
2420 cleanup_post(forall(AllIds,P,Rhs),pred,I,NewPred,pred,INew,multi/forall_splitting) :-
2421 AllIds = [TID1|TRestIDs], TRestIDs = [_|_], % TO DO: maybe not require that TID1 is the first id
2422 get_preference(use_clpfd_solver,true), % with CLPFD false: maybe more likely to reduce performance
2423 % NOTE: we could destroy symmetry reduction detection if TRestIDs = [TID2], but we run after symmetry detection
2424 % !(x,y,...).(x:SET & RestPred => Rhs) == !x.(x:SET => !(y,..).(RestPred => Rhs))
2425 conjunction_to_list(P,[MEM|RestPreds]),
2426 is_membership(MEM,TID,Set),
2427 same_id(TID1,TID,ID),
2428 ? \+ definitely_infinite(Set), % prevent !(x,y).(x:NATURAL & x<10 & y :1..x => x+y<20)
2429 %\+ known_set(Set), % rewriting makes sense if Set is not fully known and will be instantiated during solving
2430 % used to prevent known sets, but rewriting also useful for known sets (QueensWithEvents_ForallTest2b)
2431 get_sorted_ids(TRestIDs,RestIDs),
2432 not_occurs_in_predicate(RestIDs,Set),
2433 NewPred = forall([TID1],MEM,InnerForall),
2434 conjunct_predicates_with_pos_info(RestPreds,InnerForallLhs),
2435 construct_inner_forall(TRestIDs,InnerForallLhs,Rhs,I,InnerForall),
2436 !,
2437 delete(I,used_ids(_),I1), % should in principle still be ok at outer level; but just be sure
2438 add_removed_typing_info(I1,INew),
2439 (debug_mode(on) -> format('FORALL SPLITTING ~w (from ~w) for better propagation: ',[ID,RestIDs]),
2440 print_bexpr(b(NewPred,pred,INew)),nl
2441 ; true).
2442 cleanup_post(exists([TID],MemPred),pred,IOld,
2443 Res,pred,IOld, single/replace_exists_by_not_empty) :-
2444 % simplify #ID.(ID:E) <=> E /= {}
2445 % simplify #ID.(ID:E1 & ID:E2) <=> E1 /\ E2 /= {} , etc...
2446 % important e.g. for y:20..30000000000 & not(#x.(x:1..10 & x:8..y))
2447 ? is_valid_id_member_check(MemPred,TID,E),
2448 !,
2449 (definitely_not_empty_set(E) -> Res= truth
2450 ; get_texpr_type(E,Type), EmptySet=b(empty_set,Type,[]),
2451 Res = not_equal(E,EmptySet)),
2452 (debug_mode(off) -> true
2453 ; get_texpr_id(TID,ID),
2454 format('Removing existential quantifier: ~w~n',[ID]),
2455 print_bexpr(b(Res,pred,IOld)),nl).
2456 cleanup_post(exists([TID],b(NotMemPred,_,_)),pred,IOld,
2457 not_equal(E,TypeExpr),pred,IOld, single/replace_exists_by_not_full) :-
2458 % simplify #ID.(ID/:E) <=> E /= FullType
2459 % important e.g. for y:7..30000000000 & not(#x.(x /: 1..y))
2460 is_not_member(NotMemPred,MID,E),
2461 same_id(TID,MID,SID),
2462 % + check that MID does not occur in E
2463 \+ occurs_in_expr(SID,E),
2464 get_texpr_type(E,SType),
2465 is_set_type(SType,Type),
2466 create_maximal_type_set(Type,TypeExpr), % Note: no longer introduces identifiers but value(.) results
2467 !,
2468 (debug_mode(off) -> true
2469 ; format('Removing existential quantifier: ~w~n',[SID]),
2470 print_bexpr(b(not_equal(E,TypeExpr),pred,IOld)),nl).
2471 cleanup_post(exists([TID],b(Pred,_,_)),pred,IOld,
2472 truth,pred,IOld, single/replace_exists_by_truth) :-
2473 b_interpreter_check:arithmetic_op(Pred,_Op,X,Y),
2474 ( (same_id(TID,X,SID), \+ occurs_in_expr(SID,Y), always_well_defined_or_disprover_mode(Y)) ;
2475 (same_id(TID,Y,SID), \+ occurs_in_expr(SID,X), always_well_defined_or_disprover_mode(X))
2476 ),
2477 !, % we have a formula of the form #SID.(SID > Expr); provided Expr is well-defined, this is always true
2478 (debug_mode(off) -> true
2479 ; format('Removing existential quantifier: ~w~n',[SID]),
2480 print_bexpr(b(Pred,pred,[])),nl).
2481 cleanup_post(exists([TID1,TID2|OTHER],RHS),pred,IOld,
2482 exists([TID1,TID2|OTHER],NewRHS),pred,[prob_symmetry(ID1,ID2)|IOld],single/symmetry_detection) :-
2483 % DETECT Symmetries such as #(x,y).(x /= y & (x=TRUE or y=TRUE))
2484 % #(x2,y).(x2 /= y & x2:s & y:s & x2=aa or y=aa)
2485 get_texpr_type(TID1,T), get_texpr_type(TID2,T),
2486 \+ preferences:get_preference(use_solver_on_load,kodkod),
2487 preferences:get_preference(use_static_symmetry_detection,true),
2488 sym_break_supported_type(T), % LESS not yet fully functional with SET types; TO DO: fix
2489 get_texpr_id(TID1,ID1), get_texpr_id(TID2,ID2),
2490 nonmember(prob_symmetry(ID1,ID2),IOld),
2491 ? \+(contains_equality(TID1,TID2,RHS)), % IDs are already equal; no use in sym breaking
2492 ? rename_bt(RHS,[rename(ID1,ID2),rename(ID2,ID1)],RHS2),
2493 same_norm_texpr(RHS,RHS2),
2494 construct_sym_break(T,TID1,TID2,RHS,SYMBREAK),
2495 conjunct_predicates_with_pos_info(RHS,SYMBREAK,NewRHS),
2496 (debug_mode(off) -> true
2497 ; format('SYMMETRY BREAKING EXISTS: #(~w,~w).(',[ID1,ID2]),print_bexpr(NewRHS),print(')'),nl).
2498 cleanup_post(Expr,T,I1,NewExpr,T,I1,single/detect_lambda_result_quant_auto) :-
2499 construct_for_find_do_not_enumerate(Expr,KIND,TIds,Body,NewExpr,NewBody),
2500 perform_do_not_enumerate_analysis(TIds,Body,KIND,I1,NewBody).
2501 % sort args of commutative operators by term size
2502 cleanup_post(Expr, Type, I, NExpr, Type, NI, single/normalize_commutative_args) :-
2503 preferences:get_preference(normalize_ast_sort_commutative, true),
2504 sort_commutative_args(Expr, I, NExpr, NI).
2505 %,(NExpr=Expr -> true ; print('COMMUTE: '), translate:print_bexpr(b(Expr,Type,I)),nl, print(' TO: '), translate:print_bexpr(b(NExpr,Type,NI)),nl).
2506 %% COMMENT IN NEXT LINE TO CHECK validity of AST per NODE (helps find bugs)
2507 %%cleanup_post(Expr,pred,I,Expr,pred,I,single/checked) :- check_ast(true,b(Expr,pred,I)),fail.
2508 %%
2509 cleanup_post(Expr, pred, I, Expr, pred, [DI|I], single/detect_prob_ignore) :-
2510 ? get_info_labels(I,Labels), member(Label,Labels),
2511 ? is_prob_ignore_label(Label),
2512 !,
2513 DI=description('prob-ignore'), % detected by info_has_ignore_pragma/1
2514 nonmember(DI,I),
2515 add_message(detect_prob_ignore,'Detected prob-ignore label: ',Label,I).
2516
2517 is_prob_ignore_label(Label) :-
2518 atom_codes(Label,Cs),
2519 IGNORE = [112,114,111,98,DASH,105,103,110,111,114,101|_],
2520 % used to be: append("prob-ignore",_,IGNORE), but Rodin editor sometimes puts Dash 8722 rather than 45 in label
2521 ? suffix(Cs,IGNORE), % accept prob-ignore somewhere in the label
2522 ? member(DASH,[45, 8722, 95, 46, 32, 126, 61, 43, 35]). % "--_. ~=+#"
2523 % used to call reverse and match "erongi-borp"
2524
2525 cleanup_post_function(Override,X,_Type,I0,Res,Info,multi/function_override) :-
2526 preferences:get_preference(disprover_mode,true), % only applied in Disprover mode as it can remove WD problem; TO DO make it also applicable in normal mode
2527 get_texpr_expr(Override,overwrite(_F,SEXt)),
2528 SEXt = b(set_extension(LIST),_,_),
2529 member(b(couple(From,To),_,_),LIST),
2530 same_texpr(From,X),
2531 % ( F <+ { ... X|->To ...}) (X) ==> To
2532 %print_bexpr(b(function(Override,X),Type,_I)), print(' ==> '), print_bexpr(To),nl,
2533 !,
2534 get_texpr_expr(To,Res),
2535 get_texpr_info(To,I1),
2536 add_important_info_from_super_expression(I0,I1,Info).
2537 cleanup_post_function(Override,X,Type,Info,Res,Info,multi/function_override_ifte) :-
2538 preferences:get_preference(disprover_mode,true), % only applied in Disprover mode as it can remove WD
2539 % TO DO: should we do this generally? or simply deal with overwrite symbolically always?
2540 get_texpr_expr(Override,overwrite(F,SEXt)),
2541 SEXt = b(set_extension([Couple]),_,_),
2542 Couple = b(couple(From,To),_,_),
2543 % (f <+ {A|->B}) (x) -> if_then_else(x=A,B,f(x)) ; avoids having to explicitly compute f<+{A|->B}
2544 Res = if_then_else(EqXFrom,To,FX),
2545 safe_create_texpr(equal(X,From),pred,EqXFrom),
2546 safe_create_function_call(F,X,Type,Info,FX).
2547 cleanup_post_function(SEXt,ARG,_Type,I0,Res,Info,multi/function_set_extension) :-
2548 SEXt = b(set_extension(LIST),_,ListInfos), % TO DO: also support b(value(avl_set(A)),_,_)
2549 eval_set_extension_element(ARG,Value,not_available),
2550 ? select(b(couple(LHS,RHS),_,_),LIST,REST),
2551 ? (member(contains_wd_condition,ListInfos) % then we could remove WD problem, e.g., r = {1|->2, 2|-> 1/0}(1)
2552 -> (preferences:preference(find_abort_values,false) ;
2553 preferences:get_preference(disprover_mode,true))
2554 ; true),
2555 eval_set_extension_element(LHS,Value,not_available), %nl,print(found(RHS)),nl,
2556 % WE NEED TO Check that all LHS can be compared against ARG
2557 \+ member((b(couple(LHS2,_),_,_),REST),eval_set_extension_element(LHS2,Value,not_available)), % no other potential match
2558 \+ member((b(couple(LHS3,_),_,_),LIST), \+ eval_set_extension_element(LHS3,_,not_available)), % all left-hand-sides can be evaluated
2559 !, get_texpr_expr(RHS,Res), get_texpr_info(RHS,I1),
2560 add_important_info_from_super_expression(I0,I1,Info).
2561 % Detect if_then_else in format as printed by pp_expr2(if_then_else( ....)...) or as generated by B2TLA:
2562 cleanup_post_function(IFT,DUMMYARG,_Type,Info,if_then_else(IFPRED,THEN,ELSE),Info,multi/function_if_then_else) :-
2563 ? is_if_then_else(IFT,post,DUMMYARG,IFPRED,THEN,ELSE),
2564 (debug_mode(off) -> true
2565 ; print('% Recognised if-then-else expression: IF '), print_bexpr(IFPRED),
2566 print(' THEN '),print_bexpr(THEN), print(' ELSE '),print_bexpr(ELSE),nl
2567 ).
2568 cleanup_post_function(Composition,X,Type,Info,NewExpr,Info,multi/function_composition) :-
2569 (data_validation_mode ;
2570 get_preference(convert_comprehension_sets_into_closures,true)
2571 % there it can make a big difference in particular since relational composition (rel_composition_wf -> rel_compose_with_inf_fun case) was not fully symbolic; see Systerel data validation examples
2572 ),
2573 % (F;G)(X) --> G(F(X)) (F;G;H)(X) --> H(G(F(X))) ...
2574 peel_rel_composition(Composition,Type,Info,X,Result,Level),
2575 Level>0,
2576 Result = b(NewExpr,_,_),
2577 %check_ast(Result), % <---
2578 (debug_mode(off) -> true
2579 ; format('Function application of COMPOSITION (Nesting: ~w) translated to: ',[Level]),print_bexpr(Result),nl).
2580 cleanup_post_function(Fun,Arg,_Type,Info,function(Fun,Arg),NewInfo,single/function_inversion_annotation) :-
2581 data_validation_mode, % TODO: activate in general
2582 limited_propagation(Arg),
2583 NewInfo = [prob_annotation('INVERSION_PENALTY')|Info],
2584 (debug_mode(off) -> true
2585 ; add_message(ast_cleanup,'Function application not suited for propagation from result to argument: ',Arg,Info)).
2586
2587 % statically detect whether there is potential for propagating result values onto these expressions
2588 limited_propagation(b(Expr,_,_)) :- limited_prop_aux(Expr).
2589 limited_prop_aux(function(_,_)). % we need to propagate through at least one more function call
2590 limited_prop_aux(composition(_,_)). % argument is a function, composed of two other functions
2591 limited_prop_aux(iteration(_,_)).
2592 limited_prop_aux(record_field(Rec,_)) :- limited_propagation(Rec). % we only know part of the record; TODO: add a penalty even if Rec allows propagation
2593 %limited_prop_aux(external_function_call(_,_)). % MU probably ok, for other funs it depends
2594 limited_prop_aux(couple(A,B)) :-
2595 (limited_propagation(A)
2596 -> % back propagation on A not useful,
2597 (limited_propagation(B) -> true % back propagation on both arguments is not useful
2598 ; is_constant(B) % B is a constant and could only filter (if TRY_FIND_ABORT / find_abort_values false)
2599 )
2600 ; is_constant(A), limited_propagation(B) % what if both are a constant ?
2601 ).
2602 limited_prop_aux(minus(A,B)) :- (limited_propagation(A) -> true ; limited_propagation(B)).
2603 limited_prop_aux(add(A,B)) :- (limited_propagation(A) -> true ; limited_propagation(B)).
2604 limited_prop_aux(div(A,B)) :- (limited_propagation(A) -> true ; limited_propagation(B)).
2605 limited_prop_aux(multiplication(A,B)) :- (limited_propagation(A) -> true ; limited_propagation(B)).
2606 limited_prop_aux(let_expression(_,_,C)) :- limited_propagation(C).
2607 % TODO: detect more cases where propagating from result of function application to argument is of limited value
2608 % sequence operators: insert_tail, first, last, ..., sequence_extension (cf test 2387)
2609
2610 is_constant(b(C,_,_)) :- is_const_aux(C).
2611 is_const_aux(boolean_false).
2612 is_const_aux(boolean_true).
2613 is_const_aux(couple(A,B)) :- is_constant(A),is_constant(B).
2614 is_const_aux(empty_set).
2615 is_const_aux(empty_sequence).
2616 is_const_aux(integer(_)).
2617 is_const_aux(real(_)).
2618 is_const_aux(string(_)).
2619 % not covered yet: value(_) and record(_)
2620
2621 :- use_module(closures,[is_recursive_closure/3]).
2622 % detect comprehension set or closure values that can be inlined in member/not_member checks
2623 is_comprehension_set(comprehension_set(TypedIds,Body),TypedIds,Body).
2624 is_comprehension_set(value(Closure),TypedIds,Body) :- nonvar(Closure),
2625 Closure = closure(P,T,Body),
2626 ? \+ is_recursive_closure(P,T,Body), % otherwise inlining may expose unbound rec. ID, see test 554
2627 \+ custom_explicit_sets:is_interval_closure_or_integerset(Closure,_,_), % this is already a value
2628 % TO DO: also detect simple member closures like seq(0..1)
2629 create_typed_ids(P,T,TypedIds).
2630
2631 cleanup_comprehension_set([TID],b(member(LHS,TSet),pred,_),Type,I,Set,I2,multi/remove_useless_comprehension_set) :-
2632 get_texpr_id(TID,ID),
2633 get_texpr_id(LHS,ID),
2634 TSet=b(Set,Type,I2),
2635 (member(prob_annotation('SYMBOLIC'),I)
2636 -> % maybe this set comprehension was created with the purpose of adding the symbolic annotation
2637 % e.g., Set = closure(SET) stemming from /*@symbolic*/ {x|x:closure1(SET)}
2638 fail % TODO: see if we can propagate the symbolic annotation to TSet
2639 ; true),
2640 % {ID|ID:Set} ==> Set
2641 not_occurs_in_expr(ID,TSet),
2642 !,
2643 add_hint_message(remove_useless_comprehension_set,'Removing useless comprehension set over: ',ID,I).
2644 cleanup_comprehension_set([TID],Body,_Type,I,NewExpr,NewInfo,single/detect_seq_comprehension_set) :-
2645 get_texpr_id(TID,ID),
2646 % {ID | #LenID. (ID : 1..LenID --> Set)} ==> seq(Set)
2647 % {ID | #LenID. (ID : 1..LenID >-> Set)} ==> iseq(Set)
2648 get_texpr_expr(Body,exists([TLen],TIBody)),
2649 get_texpr_id(TLen,LenID), LenID \= ID,
2650 get_texpr_expr(TIBody,IBody),
2651 ? get_member(IBody,LenID,ISet,TID2,FUNCTION),
2652 get_texpr_id(TID2,ID),
2653 ? get_seq_fun_aux(FUNCTION,ISet,Interval,SeqTypeSet),
2654 get_texpr_expr(Interval,interval(ONE,TLen2)),
2655 ? get_texpr_id_with_offset(TLen2,LenID,Offset), % LenID or something like LenID-1
2656 get_integer(ONE,StartingIndex),!,
2657 (StartingIndex = 1, Offset=0 % TODO: check if a negative offset is always ok for all Seq Types
2658 -> add_hint_message(detect_seq_comprehension_set,'Detecting sequence operator: ',ID,I),
2659 NewExpr = SeqTypeSet, NewInfo=I
2660 ; % we have something sequence like but with indexes not starting at 1, maybe at 0
2661 % e.g. {ID | #LenID. (ID : 0..LenID-1 --> Set)}; happens in Soton/UML-B drone model
2662 add_hint_message(detect_seq_comprehension_set,'Marking sequence like operator as symbolic, indexes are not starting at 1: ',ID,I),
2663 NewExpr = comprehension_set([TID],Body),
2664 %add_texpr_infos(Body,[prob_annotation('SYMBOLIC')],Body2),
2665 add_info_if_new(I,prob_annotation('SYMBOLIC'),NewInfo)
2666 ).
2667 % {RANGE_LAMBDA__|#x.(x : dom(F) & RANGE_LAMBDA__ = F(x))} --> ran(F) // generated by TLC4B -> TLA2B
2668 % TO DO: detect {R|R:INTEGER & #D.(D|->R:F)} as ran(F)
2669 cleanup_comprehension_set([TID],Body, _Type, I, range(Func), I, multi/detect_tla_range_comprehension_set) :-
2670 Body = b(exists([DomTID],EBody),pred,_),
2671 EBody = b(conjunct(LHS,RHS),pred,_),
2672 is_membership(LHS,DomTID1,b(domain(Func),_,_)),
2673 same_id(DomTID,DomTID1,_),
2674 is_equality(RHS,TID1,FunCall),
2675 FunCall = b(function(Func1,DomTID2),_,_),
2676 same_id(TID,TID1,_),
2677 same_id(DomTID,DomTID2,_),
2678 same_texpr(Func,Func1),
2679 always_well_defined_or_disprover_mode(FunCall), % we could also allow TLA minor mode
2680 add_hint_message(detect_tla_range_comprehension_set,'Detected range set-comprehension: ',Func,I).
2681 cleanup_comprehension_set([TID],Pred,Type,I,
2682 struct(b(rec(NewFieldSets),record(FieldTypes),I)),
2683 I,single/simplify_record) :-
2684 % {r|r'a : 1..1000 & r'b : 1..100 & r:struct(a:INTEGER,b:NAT,c:BOOL)} --> struct(a:1..1000,b:1..100,c:BOOL)
2685 % these kind of set comprehensions are generated by ProZ, see ROZ example model.tex test 1858
2686 % TO DO: maybe generalise this optimisation: currently it only works if all predicates can be assimilated into struct expression
2687 TID = b(identifier(ID),record(FieldTypes),_),
2688 conjunction_to_list(Pred,PL),
2689 l_update_record_field_membership(PL,ID,[],FieldSetsOut),
2690 maplist(construct_field_sets(FieldSetsOut),FieldTypes,NewFieldSets),
2691 (debug_mode(off) -> true
2692 ; print('Detected Record set comprehension: '),
2693 print_bexpr(b(struct(b(rec(NewFieldSets),record(FieldTypes),I)),Type,I)),nl).
2694 cleanup_comprehension_set(Ids1,E,_Type,I,comprehension_set(Ids2,E2),I,single/detect_lambda) :-
2695 preferences:get_preference(detect_lambdas,true),
2696 % used to lead to *** Enumerating lambda result warnings for test 1162, not anymore
2697 % does not yet detect: f = {x,y|x:NATURAL & (x> 1 &y=x+2)} & res = f[3..4]
2698 E = b(conjunct(LHS,Equality),pred,Info),
2699 nonmember(prob_annotation('LAMBDA'),Info), % not already processed
2700 ? identifier_equality(Equality,ID,TID1,Expr1),
2701 last(Ids1,TID), get_texpr_id(TID,ID),
2702 not_occurs_in_expr(ID,Expr1),
2703 not_occurs_in_predicate([ID],LHS),
2704 !,
2705 get_texpr_info(Equality,EqInfo),
2706 get_unique_id_inside('_lambda_result_',LHS,Expr1,ResultId), % currently the info field lambda_result is not enough: several parts of the ProB kernel match on the identifier name '_lambda_result_'
2707 TID1 = b(identifier(_),Type1,Info1),
2708 add_texpr_infos(b(identifier(ResultId),Type1,Info1),[lambda_result(ResultId),lambda_result_id_was(ID)],TID2),
2709 Equality2 = b(equal(TID2,Expr1),pred,[prob_annotation('LAMBDA-EQUALITY')|EqInfo]),
2710 E2 = b(conjunct(LHS,Equality2),pred,[prob_annotation('LAMBDA')|Info]),
2711 append(Ids0,[_],Ids1),
2712 append(Ids0,[TID2],Ids2),
2713 % code exists which is simpler, but has disadvantage of losing position info for equality
2714 (debug_mode(off) -> true ; format('Lambda using ~w detected: ',[ID]),print_bexpr(E2),nl).
2715
2716
2717 % extract membership for ID and detect optional restrictions for Length identfier LenID
2718 get_member(conjunct(TA,TB),LenID,ISet,TID2,FUNCTION) :-
2719 get_texpr_expr(TA,A), % detect LenId : NATURAL(1)
2720 ? get_mem_of_integerset(A,LenID,ISet), % TO DO: detect LenID>0, or LenID /=0
2721 get_texpr_expr(TB,B),
2722 get_member1(B,TID2,FUNCTION).
2723 get_member(IBody,_,'NATURAL',TID2,F) :- get_member1(IBody,TID2,F).
2724 get_member1(member(TID2,b(FUNCTION,_,_)),TID2,FUNCTION).
2725
2726 get_mem_of_integerset(member(TID2,b(SET,_,_)),LenID,ISet) :- !,
2727 get_texpr_id(TID2,LenID),
2728 is_integer_set(SET,ISet).
2729 get_mem_of_integerset(Pred,LenID,ISet) :-
2730 ? is_integer_set_constraint_pred(Pred,LenID,ISet).
2731
2732
2733 get_texpr_id_with_offset(Expr,ID,0) :- get_texpr_id(Expr,ID).
2734 get_texpr_id_with_offset(b(add(TID,Expr),integer,_),ID,Offset) :-
2735 get_texpr_id(TID,ID), get_integer(Expr,Offset).
2736 get_texpr_id_with_offset(b(minus(TID,Expr),integer,_),ID,NegOffset) :-
2737 get_texpr_id(TID,ID), get_integer(Expr,Offset), NegOffset is -Offset.
2738
2739 get_seq_fun_aux(total_function(Interval,TargetSet),'NATURAL',Interval,seq(TargetSet)).
2740 get_seq_fun_aux(total_function(Interval,TargetSet),'NATURAL1',Interval,seq1(TargetSet)).
2741 get_seq_fun_aux(total_injection(Interval,TargetSet),'NATURAL',Interval,iseq(TargetSet)).
2742 get_seq_fun_aux(total_injection(Interval,TargetSet),'NATURAL1',Interval,iseq1(TargetSet)).
2743 get_seq_fun_aux(total_bijection(Interval,TargetSet),'NATURAL',Interval,perm(TargetSet)).
2744 get_seq_fun_aux(total_bijection(Interval,TargetSet),'NATURAL1',Interval,perm(TargetSet)) :-
2745 definitely_not_empty_set(TargetSet).
2746
2747 % Detect TLA real division defined by Div_1(a, b) == CHOOSE({m|m:REAL & m*b=a})
2748 is_tla_real_division(external_function_call('CHOOSE',[SETCOMPR]),TA,TB) :-
2749 get_texpr_expr(SETCOMPR,comprehension_set([TID1],BODY)),
2750 get_texpr_id(TID1,ID),
2751 is_equality( BODY, MUL, TA),
2752 get_texpr_expr(MUL,multiplication_real(TID2,TB)),
2753 get_texpr_id(TID2,ID).
2754
2755
2756 % --------------------------------
2757
2758 construct_for_find_do_not_enumerate(exists(TIds,Pred),'EXISTS',TIds,Pred,exists(TIds,Pred2),Pred2).
2759 construct_for_find_do_not_enumerate(any(TIds,Pred,Body),'ANY',TIds,Pred,any(TIds,Pred2,Body),Pred2) :-
2760 data_validation_mode. % as we do not examine Body of the Any, we do not know if there are additional constraints on TIds in the body
2761 % tests where ANYs would be annotated 471, 565, 808, 1196, 1489, 1850
2762
2763 % try and perform analysis for a body of either exists, any or set_comprehension
2764 perform_do_not_enumerate_analysis(TIds,Body,KIND,Span,NewBody) :-
2765 get_preference(perform_enumeration_order_analysis,true),
2766 get_texpr_info(Body,BI),
2767 nonmember(prob_annotation('DO_NOT_ENUMERATE'(_)),BI), % analysis was already performed or manually annotated
2768 find_do_not_enumerate_variables(TIds,Body,SortedVs,DelayVsInOrder),
2769 !,
2770 findall(prob_annotation('DELAY_ENUMERATION'(PosNr,DNID)),nth1(PosNr,DelayVsInOrder,DNID),I1),
2771 (SortedVs = []
2772 -> NewInfos = [prob_annotation('DO_NOT_ENUMERATE'('$$NONE$$'))|I1] % dummy marking to avoid running analysis again
2773 ; findall(prob_annotation('DO_NOT_ENUMERATE'(DNID)),member(DNID,SortedVs),NewInfos,I1)
2774 ),
2775 (debug_mode(off) -> true
2776 ; I1=[], SortedVs=[] -> true
2777 ; ajoin(['Annotating ',KIND,' identifiers with DO_NOT_ENUMERATE: '],Msg),
2778 %write(SortedVs),nl,
2779 add_message(detect_lambda_result_auto,Msg,SortedVs:DelayVsInOrder,Span)
2780 ),
2781 add_texpr_infos(Body,NewInfos,NewBody).
2782 perform_do_not_enumerate_analysis(_,Body,_,_,Body).
2783
2784 :- public check_do_not_enum_result/2.
2785 % check if there is a difference with stored result in info field if it exists
2786 check_do_not_enum_result(NewInfos,BInfo) :- member(prob_annotation('DO_NOT_ENUMERATE'(_)),BInfo),!,
2787 findall(DNID,
2788 (member(prob_annotation('DO_NOT_ENUMERATE'(DNID)),BInfo), DNID \= '$$NONE$$'), OldIds),
2789 findall(DNID,
2790 (member(prob_annotation('DO_NOT_ENUMERATE'(DNID)),NewInfos), DNID \= '$$NONE$$'), NewIds),
2791 (OldIds = NewIds
2792 -> format('Same DO_NOT_ENUMERATE result: ~w~n',[OldIds])
2793 ; format('Difference in DO_NOT_ENUMERATE result:~nOLD: ~w~nNEW: ~w~n',[OldIds,NewIds])
2794 ).
2795 check_do_not_enum_result(_,_).
2796
2797 % --------------------
2798
2799 % we only sort at the top-level, as cleanup_post will work its way bottom-up:
2800 sort_commutative_args(Expr, I, Sorted, NI) :- nonvar(Expr),
2801 functor(Expr, Functor, 2),
2802 is_commutative(Functor),
2803 !,
2804 arg(1, Expr, Lhs),
2805 arg(2, Expr, Rhs),
2806 remove_all_infos_and_ground(Lhs,CNLhs), % remove infos for comparison
2807 remove_all_infos_and_ground(Rhs,CNRhs),
2808 get_texpr_expr(CNLhs,N1),
2809 get_texpr_expr(CNRhs,N2),
2810 ( N1 @> N2
2811 -> Sorted =.. [Functor,Rhs,Lhs],
2812 NI = [was(Expr)|I]
2813 ; Sorted =.. [Functor,Lhs,Rhs],
2814 NI = I
2815 ).
2816
2817
2818 is_commutative(conjunct).
2819 is_commutative(disjunct).
2820 is_commutative(equivalence).
2821 is_commutative(equal).
2822 is_commutative(not_equal).
2823 is_commutative(add).
2824 is_commutative(multiplication).
2825 is_commutative(union).
2826 is_commutative(intersection).
2827
2828 % --------------------
2829
2830 factor_disjunct(CEquality1,CEquality2,IOld,New,INew) :-
2831 % (x=2 & y=3) or (x=2 & y=4) -> x=2 & (y=3 or y=4) to improve constraint propagation
2832 Blacklist=[],
2833 conjunction_to_list(CEquality1,Preds1),
2834 conjunction_to_list(CEquality2,Preds2),
2835 ? select_equality(TId1,Preds1,Blacklist,TEqual,Expr1,RestPreds1,_,check_well_definedness), % also allow other preds, use safe_select(check_well_definedness,TEqual,Preds,Rest),
2836 get_texpr_id(TId1,Id),
2837 get_texpr_id(TId2,Id),
2838 ? select_equality(TId2,Preds2,Blacklist,_,Expr2,RestPreds2,_,check_well_definedness),
2839 same_texpr(Expr1,Expr2),
2840 conjunct_predicates_with_pos_info(RestPreds1,P1),
2841 conjunct_predicates_with_pos_info(RestPreds2,P2),
2842 % TO DO: do not recursively start from scratch in P1, one should start from the right of CEquality1:
2843 (fail, % disable recursive looking
2844 factor_disjunct(P1,P2,IOld,P12,INew) -> NewDisj = b(P12,pred,INew)
2845 ; disjunct_predicates_with_pos_info(P1,P2,NewDisj)),
2846 conjunct_predicates_with_pos_info(TEqual,NewDisj,NewPred),
2847 NewPred=b(New,pred,I2),
2848 include_important_info_from_removed_pred(IOld,I2,INew).
2849
2850 % ------------------------------------------
2851
2852 gen_rename(TID1,TID2,rename(ID1,ID2)) :- def_get_texpr_id(TID1,ID1), def_get_texpr_id(TID2,ID2).
2853
2854 is_not_member(not_member(LHS,RHS),LHS,RHS).
2855 is_not_member(negation(b(member(LHS,RHS),pred,_)),LHS,RHS).
2856
2857
2858 :- use_module(typing_tools,[create_maximal_type_set/2]).
2859 is_valid_id_member_check(b(member(MID,E),_,_),ID,E) :- same_id(ID,MID,SID),
2860 % + check that MID does not occur in E
2861 \+ occurs_in_expr(SID,E).
2862 is_valid_id_member_check(b(truth,_,_),ID,TypeExpr) :-
2863 get_texpr_type(ID,SType),
2864 create_maximal_type_set(SType,TypeExpr). % Note: this no longer introduces identifiers, which could clash
2865 is_valid_id_member_check(b(conjunct(A,B),_,_),ID,Res) :-
2866 ? is_valid_id_member_check(A,ID,EA),
2867 ? is_valid_id_member_check(B,ID,EB),
2868 get_texpr_type(EA,Type),
2869 safe_create_texpr(intersection(EA,EB),Type,Res).
2870
2871 contains_equality(TID1,TID2,RHS) :-
2872 ? b_interpreter:member_conjunct(b(equal(A,B),pred,_),RHS,_),
2873 (same_id(A,TID1,_),same_id(B,TID2,_) ; same_id(A,TID2,_),same_id(B,TID1,_)).
2874
2875 simplify_let_subst(Ids,Pred,Subst,NIds,RestPred,NewSubst) :-
2876 % remove let identifiers whose definitions are very simple, i.e. identifiers
2877 Eq = b(equal(TypID,TExpr),pred,_),
2878 can_be_optimized_away(TypID),
2879 get_texpr_id(TypID,ToReplace),
2880 b_interpreter:member_conjunct(Eq,Pred,RestPred),
2881 is_simple_expression(TExpr),
2882 nth0(_N,Ids,TI,NIds),get_texpr_id(TI,ToReplace),
2883 !,
2884 % Intitially there was an issue as we may also replace in the LHS of assignments
2885 % see e.g. TestLet = LET cnt BE cnt=1 IN IF cnt=0 THEN ABORT ELSE cnt :: {0,1} END END; in SubstitutionLaws
2886 % However, now the static type checker rejects those assignments
2887 replace_id_by_expr(Subst,ToReplace,TExpr,NSubst),
2888 % TO DO: it seems like cleanup rules are not applied on NSubst, e.g., function for set_extension rules
2889 debug_println(9,replaced_let_subst_id(ToReplace)),
2890 (Subst==NSubst -> NewSubst=NSubst ; clean_up(NSubst,[],NewSubst)).
2891
2892 can_be_optimized_away(b(_,_,I)) :- nonmember(do_not_optimize_away,I).
2893
2894 %replace_in_rhs(ID,E,RHS,CleanNewRHS) :- replace_id_by_expr(RHS,ID,E,NewRHS), clean_up(NewRHS,[],CleanNewRHS).
2895
2896 can_be_replaced(RHS,_,Ids) :- get_texpr_id(RHS,RHSID),!,
2897 ? \+ (member(TID2,Ids), get_texpr_id(TID2,RHSID)). % ID occurs in Ids, replacing it in Expr will move the scope
2898 % example: Z Test (\LET x==1 @ (\LET x==x+1; y==x @ 7*x+y)) = 15
2899 can_be_replaced(_RHS,UsedIds,Ids) :- % TO DO: compute used ids
2900 %find_identifier_uses(RHS,[],UsedIds),
2901 get_texpr_ids(Ids,AtomicIds), sort(AtomicIds,SortedIds),
2902 \+ ord_intersect(UsedIds,SortedIds).
2903
2904 % simplify LET Ids BE Ids=Exprs IN Expr END by moving one identifier Id inside
2905 simplify_let(Ids,Exprs,Expr,NIds,NExprs,CleanNewExpr) :-
2906 ? nth0(N,Ids,TId,NIds),
2907 get_texpr_id(TId,Id),
2908 can_be_optimized_away(TId),
2909 nth0(N,Exprs,LetExpr,NExprs),
2910 find_identifier_uses_if_necessary(LetExpr,[],LetExprIds),
2911 \+ ord_member(Id,LetExprIds), %\+ occurs_in_expr(Id,LetExpr), % illegal let, e.g., i = i+1;
2912 can_be_replaced(LetExpr,LetExprIds,Ids), % moving LetExpr will not produce scoping issues
2913 maplist(not_occurs_in_expr(Id),NExprs), % The ID is not used for defining other RHS in the same let
2914 ? simplify_let_aux(TId,Id,LetExpr,Expr,CleanNewExpr).
2915
2916 simplify_let_aux(_TId,Id,LetExpr,Expr,CleanNewExpr) :-
2917 % remove let identifiers whose definitions are very simple, i.e. identifiers
2918 is_simple_expression(LetExpr),
2919 % TId = LetExpr
2920 % TO DO: do not do this to outer variables which the user cares about !!
2921 !,
2922 %maplist(replace_in_rhs(Id,LetExpr),NExprs,NewExprs),
2923 ? replace_id_by_expr(Expr,Id,LetExpr,NExpr),
2924 NonGroundExceptions = do_not_ground_types, % see test 2493; TODO: should we pass NonGroundExceptions as parameter?
2925 ? clean_up(NExpr,NonGroundExceptions,CleanNewExpr). % clean up adjust eg used_ids info; necessary for test 568 in prob_safe_mode
2926 simplify_let_aux(TId,Id,LetExpr,Expr,CleanNewExpr) :-
2927 % push the let expression down the AST. E.g. "LET a=E IN (4*(a+z*a) + z)" would
2928 % be transformed to "4*(LET a=E IN (a+z*a)) + z"
2929 % If the final form is like "LET a=E IN a" it will be simplified to E.
2930 ? \+ do_not_to_move_let_inside(Expr),
2931 !,
2932 ( identifier_sub_ast(Expr,Id,SubPosition) ->
2933 ? prune_sub_ast_pos_list(SubPosition,Id,LetExpr,Expr,SafeSubPosition),
2934 SafeSubPosition = [_|_], % The LET can actually be moved down
2935 % SubPosition points to the highest point in the AST coveringa all occurences
2936 ? exchange_ast_position(SafeSubPosition,Expr,OldInner,NewInner,NExpr),
2937 get_texpr_type(OldInner,Type),
2938 ( get_texpr_id(OldInner,Id) -> % There is only one reference to Id,
2939 debug_format(19,'Simplified LET for ~w away, single usage~n',[Id]),
2940 NewInner = LetExpr % replace it with the expression
2941 % We need to check that we are not simply just exchanging lets with each other
2942 ; cycle_detection(Id,SafeSubPosition,Expr) -> debug_println(9,cycle(Id)),fail
2943 ; Type=pred -> % print(created_let_predicate(N,Id,SafeSubPosition,NIds)),nl,
2944 extract_important_info_from_subexpressions(LetExpr,OldInner,NewLetInfo), % maybe no longer necessary because of cleanups call below
2945 create_texpr(let_predicate([TId],[LetExpr],OldInner),pred,NewLetInfo,NewInner)
2946 ; % print(create_let_expression(TId)),nl,
2947 extract_important_info_from_subexpressions(LetExpr,OldInner,NewLetInfo), % maybe no longer necessary because of cleanups call below
2948 create_texpr(let_expression([TId],[LetExpr],OldInner),Type,NewLetInfo,NewInner)),
2949 NonGroundExceptions = do_not_ground_types, % see test 2493
2950 ? clean_up(NExpr,NonGroundExceptions,CleanNewExpr) % maybe we only need WD post rules ?
2951 ; always_well_defined_or_wd_improvements_allowed(LetExpr) ->
2952 % Id does not occur in the expression -> just remove the LET
2953 add_debug_message(b_ast_cleanup,'Identifier of LET not used: ',Id,Expr),
2954 CleanNewExpr = Expr
2955 ; gen_unused_let_id_msg(TId,Id,LetExpr),fail
2956 ),!.
2957 simplify_let_aux(TId,Id,LetExpr,Expr,CleanNewExpr) :- % do_not_to_move_let_inside has succeeded
2958 not_occurs_in_expr(Id,Expr),
2959 (always_well_defined_or_wd_improvements_allowed(LetExpr)
2960 -> add_debug_message(b_ast_cleanup,'Identifier of LET not used: ',Id,Expr)
2961 ; gen_unused_let_id_msg(TId,Id,LetExpr), fail
2962 ),
2963 CleanNewExpr=Expr.
2964
2965 ?gen_unused_let_id_msg(TID,Id,LetExpr) :- get_texpr_info(TID,Infos), member(generated_exists_parameter,Infos),!,
2966 add_debug_message(b_ast_cleanup,'Cannot remove unused identifier in (auto-generated) LET due to WD condition: ',Id,LetExpr).
2967 gen_unused_let_id_msg(_TID,Id,LetExpr) :-
2968 add_message(b_ast_cleanup,'Cannot remove unused identifier in LET due to WD condition: ',Id,LetExpr).
2969
2970
2971 % this has to be checked not just at the top-level but along the SubPosition path
2972 do_not_to_move_let_inside(b(E,_T,Infos)) :-
2973 (do_not_to_move_let_inside_aux(E) -> true
2974 ? ; E=exists(_,_), (get_preference(lift_existential_quantifiers,true) ; member(allow_to_lift_exists,Infos))
2975 ).
2976 %add_message(simplify_let,'Not moving LET inside: ',b(E,_T,Infos),Infos).
2977 % exists can be lifted which can also lead to duplication allow_to_lift_exists
2978 % for those quantifiers we may duplicate the computation of a let by moving it inside:
2979 do_not_to_move_let_inside_aux(forall(_,_,_)). % otherwise we may compute the let multiple times
2980 do_not_to_move_let_inside_aux(comprehension_set(_,_)). % ditto
2981 do_not_to_move_let_inside_aux(general_product(_,_,_)). % ditto (PI)
2982 do_not_to_move_let_inside_aux(general_sum(_,_,_)). % ditto (SIGMA)
2983 do_not_to_move_let_inside_aux(lambda(_,_,_)). % ditto
2984 do_not_to_move_let_inside_aux(quantified_intersection(_,_,_)). % ditto
2985 do_not_to_move_let_inside_aux(quantified_union(_,_,_)). % ditto
2986 %do_not_to_move_let_inside_aux(exists(_,_)). % can lead to duplication upon lifting or semi-lifting, e.g., if two exists are nested?
2987 % TODO: investigate if we should disable moving LET into exists in general
2988 do_not_to_move_let_inside_aux(convert_bool(_)). % can lead to duplication if reification fails
2989
2990
2991 not_occurs_in_expr(Id,Expr) :- \+ occurs_in_expr(Id,Expr).
2992
2993 cycle_detection(Id,SubPosition,Expr) :-
2994 ? (get_constructor(SubPosition,Expr,CC),
2995 \+ let_constructor(CC) -> fail % at least one other constructor found
2996 ; debug_println(9,cycle_let_detection(Id))
2997 ).
2998 % we have a let constructor which can be modified by simplify_let:
2999 let_constructor(let_expression).
3000 let_constructor(let_predicate).
3001 let_constructor(let_substitution).
3002
3003 % traverse a SubPositions List from identifier_sub_ast and check for potential duplication
3004 % by quantifiers, if found: prune list at that point
3005 prune_sub_ast_pos_list([],_,_,_,[]).
3006 prune_sub_ast_pos_list([Pos|T],Id,LetExpr,OldTExpr,Res) :-
3007 remove_bt(OldTExpr,OldExpr,NewExpr,_NewTExpr),
3008 (do_not_to_move_let_inside(OldTExpr)
3009 -> Res=[],
3010 (debug_mode(off) -> true ; add_message(simplify_let,'Not moving LET inside quantifier/bool: ',Id,OldTExpr))
3011 ; Res = [Pos|TR],
3012 ? syntaxtransformation(OldExpr,Subs,_Names,_NSubs,NewExpr),
3013 nth0(Pos,Subs, OldSelected,_Rest),
3014 ? prune_sub_ast_pos_list(T,Id,LetExpr,OldSelected,TR),
3015 (TR=[], avoid_top_level_let_within(OldExpr)
3016 -> Res=[] % we would create a let at the top-level of this
3017 ; Res = [Pos|TR]
3018 )
3019 ).
3020
3021 avoid_top_level_let_within(card(_)). % reification of card does not work yet with top-level let_predicate, for test 1562
3022 % Note: maybe it is best to avoid pushing into card completely, as even at the next
3023 % level the let could disturb the reification small set detection?
3024
3025 % get a SubPosition path (as produced by identifier_sub_ast) and
3026 % generate upon backtracking all constructors that are used along the Path
3027 get_constructor([Pos|T],OldTExpr,ConstructorForPos) :-
3028 remove_bt(OldTExpr,OldExpr,NewExpr,_NewTExpr),
3029 (functor(OldExpr,ConstructorForPos,_)
3030 ; syntaxtransformation(OldExpr,Subs,_Names,_NSubs,NewExpr),
3031 nth0(Pos,Subs, OldSelected,_Rest),
3032 ? get_constructor(T,OldSelected,ConstructorForPos)
3033 ).
3034
3035 is_simple_expression(TExpr) :-
3036 get_texpr_expr(TExpr,Expr),
3037 is_simple_expression2(Expr),!.
3038 is_simple_expression(TExpr) :-
3039 is_just_type(TExpr).
3040 is_simple_expression2(identifier(_)).
3041 is_simple_expression2(integer(_)).
3042 is_simple_expression2(real(_)).
3043 is_simple_expression2(string(_)).
3044 is_simple_expression2(boolean_true).
3045 is_simple_expression2(boolean_false).
3046 is_simple_expression2(empty_set).
3047 is_simple_expression2(empty_sequence).
3048 %is_simple_expression2(interval(Low,Up)) :- is_simple_expression(Low), is_simple_expression(Up).
3049 % TODO: simple couples? simple records?
3050
3051 % a variation of is_simple_expression, allowing some simple constructs
3052 is_simple_expression_lvl(TExpr,Lvl) :-
3053 get_texpr_expr(TExpr,Expr),
3054 is_simple_expression2_lvl(Expr,Lvl),!.
3055 is_simple_expression2_lvl(Cons,Lvl) :- simple_binary_constructor(Cons,A,B), !,
3056 Lvl>0, L1 is Lvl-1,
3057 is_simple_expression_lvl(A,L1),is_simple_expression_lvl(B,L1).
3058 is_simple_expression2_lvl(Cons,Lvl) :- simple_unary_constructor(Cons,A),!,
3059 Lvl>0, L1 is Lvl-1,
3060 is_simple_expression_lvl(A,L1).
3061 is_simple_expression2_lvl(E,_) :- is_simple_expression2(E).
3062
3063 simple_binary_constructor(function(A,B),A,B).
3064 simple_binary_constructor(couple(A,B),A,B).
3065 % TODO: simple records?
3066 simple_unary_constructor(reverse(A),A).
3067 simple_unary_constructor(set_extension([A]),A).
3068 simple_unary_constructor(sequence_extension([A]),A).
3069
3070 % check for duplication of complex LHS expressions by replacing ID with LHS NrOccurences of times for Rule
3071 is_replace_id_by_expr_ok(_LHS,_ID,NrOccurences,_Rule) :- NrOccurences < 2.
3072 is_replace_id_by_expr_ok(_LHS,_ID,_,_Rule) :-
3073 get_preference(normalize_ast,true),!. % is necessary at least for remove_member_comprehension, remove_not_member_comprehension
3074 is_replace_id_by_expr_ok(_LHS,_ID,_,_Rule) :-
3075 get_preference(use_common_subexpression_elimination,true),!.
3076 is_replace_id_by_expr_ok(LHS,_ID,NrOccurences,_Rule) :-
3077 (NrOccurences<3 -> Lvl=2 ; NrOccurences<6 -> Lvl=1 ; Lvl=0), % what heuristic should we use here; test 1750 seems to indicate that Lvl=4 would still be beneficial for NrOccurences=2 and lambda_guard1 rule
3078 is_simple_expression_lvl(LHS,Lvl).
3079 is_replace_id_by_expr_ok(LHS,ID,Count,Rule) :-
3080 debug_mode(on),
3081 format('replace ~w (~w times) not ok for ~w using: ',[ID,Count,Rule]), translate:print_bexpr(LHS),nl,fail.
3082
3083
3084 % detect either Event-B identity or id over full type
3085 is_event_b_identity(b(X,_,_)) :- is_event_b_identity_aux(X).
3086 is_event_b_identity_aux(event_b_identity).
3087 is_event_b_identity_aux(identity(T)) :- is_just_type(T).
3088
3089 :- use_module(library(avl),[avl_member/2]).
3090 % check if we have a set extension and return list of terms
3091 is_set_extension(b(S,T,I),L) :- is_set_extension_aux(S,T,I,L).
3092 is_set_extension_aux(set_extension(L),_,_,L).
3093 % TO DO: detect sequence_extension
3094 is_set_extension_aux(value(avl_set(A)),SetType,I,L) :- % computed by eval_set_extension
3095 is_set_type(SetType,Type),
3096 findall(b(value(M),Type,I),avl_member(M,A),L).
3097
3098 is_sequence_extension(b(S,T,I),L) :- is_sequence_extension_aux(S,T,I,L).
3099 is_sequence_extension_aux(sequence_extension(L),_,_,L).
3100 % TO DO: detect value/set_extensions
3101
3102 recursion_detection_enabled(A,B,I) :-
3103 ? (recursion_detection_enabled_aux(A,B,I) -> true).
3104 recursion_detection_enabled_aux(A,_B,I) :-
3105 animation_mode(b), % in B mode,
3106 memberchk(section(properties),I), % the rule should be only applied to properties
3107 % and where A is an abstract constant.
3108 get_texpr_info(A,AInfo),memberchk(loc(_,_,abstract_constants),AInfo).
3109 recursion_detection_enabled_aux(A,_B,_I) :-
3110 animation_minor_mode(eventb), % in Event-B,
3111 %TODO: Limit application to axioms
3112 get_texpr_info(A,AInfo), % A must be a constant
3113 memberchk(loc(_,constants),AInfo).
3114 recursion_detection_enabled_aux(_A,_B,_I) :-
3115 animation_minor_mode(z). % use always in Z
3116 recursion_detection_enabled_aux(_A,_B,Infos) :- % check for @desc recursive_let pragma
3117 member(description(D),Infos), rec_let_pragma(D).
3118
3119 rec_let_pragma(recursive_let).
3120 rec_let_pragma(letrec). % more compact exists in other languages
3121 rec_let_pragma(reclet). % Z syntax
3122
3123 % peel of relational compositions and replace with function application
3124 % used to translate (F;G)(X) --> G(F(X)) or (F;G;H)(X) --> H(G(F(X))) ...
3125 peel_rel_composition(b(composition(F,G),_,_),TypeGArg,Info,Arg,GFres,L1) :-
3126 get_texpr_type(G,SType),
3127 bsyntaxtree:is_set_type(SType,couple(TypeFArg,_)),
3128 !,
3129 %Note: rule is multi: we will detect compositions inside G at next iteration
3130 peel_rel_composition(F,TypeFArg,Info,Arg,FRes,Level), L1 is Level+1,
3131 safe_create_function_call(G,FRes,TypeGArg,Info,GFres).
3132 peel_rel_composition(Fun,TypeFArg,Info,Arg,FArg,0) :-
3133 safe_create_function_call(Fun,Arg,TypeFArg,Info,FArg). % TODO: apply function_call_opt
3134
3135 % create a function call and detect certain optimisations like lambda inlining
3136 safe_create_function_call(Fun,Arg,TypeFArg,Info,Res) :-
3137 safe_create_texpr(function(Fun,Arg),TypeFArg,Info,FArg),
3138 (cleanup_pre_function(Fun,Arg,TypeFArg,Info,CleanupRes,Info2,_)
3139 -> Res = b(CleanupRes,TypeFArg,Info2)
3140 ; Res=FArg
3141 ).
3142
3143
3144 construct_union_from_list([X],_,_,Res) :- !, Res=X.
3145 construct_union_from_list([X,Y|T],Type,Info,Res) :-
3146 construct_union_from_list([Y|T],Type,Info,RHS),
3147 Res = b(union(X,RHS),Type,Info).
3148 construct_inter_from_list([X],_,_,Res) :- !, Res=X.
3149 construct_inter_from_list([X,Y|T],Type,Info,Res) :-
3150 construct_inter_from_list([Y|T],Type,Info,RHS),
3151 Res = b(intersection(X,RHS),Type,Info).
3152
3153 % LEQ_SYM_BREAK / LEQ_SYM does not support all types yet:
3154 sym_break_supported_type(Var) :- var(Var),!,fail.
3155 sym_break_supported_type(integer).
3156 sym_break_supported_type(boolean).
3157 sym_break_supported_type(real).
3158 sym_break_supported_type(string).
3159 sym_break_supported_type(global(_)).
3160 sym_break_supported_type(couple(A,B)) :- sym_break_supported_type(A), sym_break_supported_type(B).
3161 sym_break_supported_type(record(F)) :- maplist(sym_break_supported_field,F).
3162 sym_break_supported_field(field(_,T)) :- sym_break_supported_type(T).
3163 % example with pairs: !(x,y).(x:s2 & y:s2 & x/=y => prj1(INTEGER,INTEGER)(x)/=prj1(INTEGER,INTEGER)(y)) (with let s2 = {x,y|x:1..10000 & y:{x+1}}); here we get a slow-down; maybe we should check if RHS complicated enough
3164 % here it is beneficial: !(x,y).(x:dom(s)&y:dom(s)&x/=y => s(x)+s(y)>0) with let s={x,y,v|x:1..10&y:1..50&v=x+y}; runtime goes down from 9.7 to 6.1 seconds
3165
3166 ?construct_sym_break(integer,TID1,TID2,Pred,Res) :- member_in_conjunction(Neq,Pred), is_id_inequality(Neq,TID1,TID2),
3167 !, get_texpr_info(TID1,Info1),
3168 Res = b(less(TID1,TID2),pred,Info1). % we don't need the external function; we can used <
3169 construct_sym_break(integer,TID1,TID2,_Pred,Res) :- !, get_texpr_info(TID1,Info1),
3170 Res = b(less_equal(TID1,TID2),pred,Info1). % we don't need the external function; we can used <= ; we could check whether < or <= already in Pred ? occurs in test 1360: #(vv,ww).(vv < ww & ww < vv)
3171 construct_sym_break(_,TID1,TID2,_,Res) :- get_texpr_info(TID1,Info1),
3172 Res = b(external_pred_call('LEQ_SYM',[TID1,TID2]),pred,Info1).
3173
3174 % construct {Expr1,Expr2}
3175 construct_set_extension(Expr1,Expr2,Res) :- same_texpr(Expr1,Expr2),!,
3176 get_texpr_type(Expr1,Type),
3177 extract_info(Expr1,Infos), % will also copy used_ids; ok as this does not change by adding set_extension
3178 Res = b(set_extension([Expr1]),set(Type),Infos).
3179 construct_set_extension(Expr1,Expr2,Res) :-
3180 get_texpr_type(Expr1,Type),
3181 extract_info(Expr1,Expr2,Infos),
3182 (Expr1 @=< Expr2 -> Lst=[Expr1,Expr2] ; Lst=[Expr2,Expr1]), % solves issue with ParserTests; {FALSE,TRUE}
3183 Res = b(set_extension(Lst),set(Type),Infos).
3184
3185 l_construct_set_extension([E1],[E2],Res) :- !, construct_set_extension(E1,E2,Res).
3186 l_construct_set_extension(L1,L2,Res) :- append(L1,L2,L12),
3187 L12=[Expr1|T],!,
3188 get_texpr_type(Expr1,Type),
3189 last(T,Expr2),
3190 extract_info(Expr1,Expr2,Infos), % TODO: improve info extraction; sort L12 values?
3191 Res = b(set_extension(L12),set(Type),Infos).
3192 l_construct_set_extension(A,B,Res) :-
3193 add_internal_error('Requires at least two els:',l_construct_set_extension(A,B,Res)),fail.
3194
3195 is_id_inequality(b(not_equal(A,B),pred,_),X,Y) :-
3196 (same_texpr(A,X) -> same_texpr(B,Y) ; same_texpr(A,Y), same_texpr(B,X)).
3197
3198
3199 %known_set(b(integer_set(_),set(integer),_)). % used for forall splitting; TODO: use is_integer_set ??
3200 %known_set(b(interval(_,_),set(integer),_)).
3201
3202 % detect if we have an if-then-else function (which is then applied to a dummy argument)
3203 is_if_then_else(b(comprehension_set([TDummyID1,ID2],CONJ),_Type,_),_,_DUMMYARG,IFPRED,THEN,ELSE) :-
3204 % we ignore the _DUMMYARG as here we do not check the value of DUMMYARG in the body
3205 % TO DO: also allow removal of equalities as in TLA case below
3206 % DETECT {Dummy,Res| Test => Res=THEN & not(Test) => Res=ELSE}
3207 get_texpr_id(ID2,LambdaID), get_texpr_id(TDummyID1,DummyID),
3208 ? is_ifte_case_conjunct(CONJ,IFPRED,EQ1,EQ2),
3209 ? is_equality_conj(EQ1,II1,THEN), get_texpr_id(II1,LambdaID),
3210 ? is_equality_conj(EQ2,II2,ELSE), get_texpr_id(II2,LambdaID),
3211 \+ occurs_in_expr(DummyID,IFPRED),\+ occurs_in_expr(LambdaID,IFPRED),
3212 \+ occurs_in_expr(DummyID,THEN), \+ occurs_in_expr(LambdaID,THEN),
3213 \+ occurs_in_expr(DummyID,ELSE), \+ occurs_in_expr(LambdaID,ELSE).
3214
3215 % Recognize B2TLA encodings as well: %((x).(x=0 & PRED|C1)\/%(x).(x=0 & not(PRED)|C2)) (0)
3216 %is_if_then_else(IF,_,_,_,_) :- nl,print(IF),nl,nl,fail.
3217 is_if_then_else(b(union(COMP1,COMP2),_Type,_),_,DUMMYARG,IFPRED,THEN,ELSE) :-
3218 ? if_then_else_lambda(COMP1,DUMMYARG,IFPRED,THEN),
3219 ? if_then_else_lambda(COMP2,DUMMYARG,NOT_IFPRED,ELSE),
3220 is_negation_of(IFPRED,NOT_IFPRED).
3221
3222 is_if_then_else(b(set_extension([CASE1,CASE2]),_,Info),POST,Arg,IFPRED,THEN,ELSE) :-
3223 (POST=post -> true ; data_validation_mode), % in cleanup_pre the wd info is not yet computed
3224 Arg = b(convert_bool(IFPRED),boolean,_),
3225 % {TRUE|->v1,FALSE|->v2}(bool(TEST)) --> IF TEST THEN v1 ELSE v2 END
3226 % example: {TRUE|->1,FALSE|->2}(bool(2>3)) --> IF 2>3 THEN 1 ELSE 2 END
3227 CASE1 = b(couple(b(B1,boolean,_),Val1),_,_),
3228 CASE2 = b(couple(b(B2,boolean,_),Val2),_,_),
3229 ( B1=boolean_true,B2=boolean_false -> THEN=Val1,ELSE=Val2
3230 ; B2=boolean_true,B1=boolean_false -> THEN=Val2,ELSE=Val1),
3231 (always_well_defined_or_disprover_mode(THEN),
3232 always_well_defined_or_disprover_mode(ELSE) -> true
3233 %,add_message(function_if_then_else,'Detected {TRUE|->v1,FALSE|->v2}(bool(TEST)) construct without WD condition, rewriting it to IF TEST THEN v1 ELSE v2 END','',Info)
3234 % otherwise: the transformation to IF-THEN-ELSE may remove WD problem
3235 ; silent_mode(on) -> true
3236 ; %data_validation_mode,
3237 add_message(function_if_then_else,'Detected {TRUE|->v1,FALSE|->v2}(bool(TEST)) construct with WD condition, you should probably rewrite it to IF TEST THEN v1 ELSE v2 END','',Info),
3238 true % fail
3239 ).
3240
3241 if_then_else_lambda(b(comprehension_set([TDummyID,TLAMBDAID],CONJ),_,_),DUMMYARG,IFPRED,RESULT) :-
3242 conjunction_to_nontyping_list(CONJ,CL),
3243 get_texpr_id(TDummyID,DummyID),
3244 get_texpr_id(TLAMBDAID,LambdaID),
3245 ? (remove_equality(DummyID,DUMMYVAL,CL,ConjList) % look if there is an equality for the DummyID
3246 -> same_texpr(DUMMYVAL,DUMMYARG), % TO DO: check that we apply the function with this value
3247 \+ occurs_in_expr(LambdaID,DUMMYVAL), % ensure this is really the same value
3248 \+ occurs_in_expr(DummyID,DUMMYVAL)
3249 ; ConjList=CL),
3250 ? remove_equality(LambdaID,RESULT,ConjList,RestList),
3251 \+ occurs_in_expr(LambdaID,RESULT),
3252 \+ occurs_in_expr(DummyID,RESULT), % otherwise this is not really a dummy identifier
3253 conjunct_predicates_with_pos_info(RestList,IFPRED),
3254 \+ occurs_in_expr(DummyID,IFPRED).
3255
3256 % DETECT (IFPRED => EQ1) & (not(IFPRED) => EQ2)
3257 is_ifte_case_conjunct(CONJ,IFPRED,EQ1,EQ2) :-
3258 is_a_conjunct(CONJ,IMP1,IMP2),
3259 is_an_implication_conj(IMP1,IFPRED,EQ1),
3260 is_an_implication_conj(IMP2,NOT_IFPRED,EQ2),
3261 ? is_negation_of(IFPRED,NOT_IFPRED).
3262 % TO DO: also deal with lazy_lets wrapped around
3263 %is_ifte_case_conjunct(lazy_let_pred(ID,IFPRED,CONJ),IFPRED,EQ1,EQ2) :-
3264 % is_a_conjunct(CONJ,IMP1,IMP2),
3265 % is_an_implication(IMP1,IFPRED,EQ1),
3266 % is_an_implication(IMP2,NOT_IFPRED,EQ2),
3267 % is_negation_of(IFPRED,NOT_IFPRED).
3268
3269 % detect explicit if-then-else for cleanup_post:
3270 explicit_if_then_else(if_then_else(IF,THEN,ELSE),IF,THEN,ELSE).
3271 explicit_if_then_else(if([b(if_elsif(IF,THEN),subst,_)|TAIL]),IF,THEN,ELSE) :-
3272 (TAIL = [b(if_elsif(b(truth,pred,_),EE),subst,_)|_] -> ELSE = EE
3273 ; TAIL = [] -> ELSE = b(skip,subst,[generated])
3274 ).
3275
3276 % just like is_an_implication but allow typing conjuncts (not yet removed in pre-phase)
3277 is_an_implication_conj(Pred,LHS,RHS) :- is_an_implication(Pred,LHS,RHS),!.
3278 is_an_implication_conj(b(conjunct(A,B),pred,_),LHS,RHS) :-
3279 (is_typing_predicate(A) -> is_an_implication_conj(B,LHS,RHS)
3280 ; is_typing_predicate(B) -> is_an_implication_conj(A,LHS,RHS)).
3281
3282 % just like is_equality but allow typing conjuncts (not yet removed in pre-phase)
3283 is_equality_conj(EQ,LHS,RHS) :- is_equality(EQ,LHS,RHS).
3284 is_equality_conj(b(conjunct(A,B),pred,_),LHS,RHS) :-
3285 (is_typing_predicate(A) -> is_equality_conj(B,LHS,RHS)
3286 ; is_typing_predicate(B) -> is_equality_conj(A,LHS,RHS)).
3287
3288 % remove a dummy equality from list
3289 remove_equality(ID,RHS,ConjList,Rest) :-
3290 DummyEQ = b(equal(DID,RHS),pred,_), % TO DO: also accept simple typing memberships ?
3291 get_texpr_id(DID,ID),
3292 ? select(DummyEQ,ConjList,Rest). %, print(eq(DID,RHS)),nl.
3293
3294 get_texpr_boolean(b(X,_,_),Res) :- is_boolan_expr(X,Res).
3295 is_boolan_expr(boolean_true,boolean_true).
3296 is_boolan_expr(boolean_false,boolean_false).
3297 is_boolan_expr(value(X),Res) :- nonvar(X), conv_bool_val(X,Res).
3298 conv_bool_val(pred_true,boolean_true).
3299 conv_bool_val(pred_false,boolean_false).
3300
3301 is_typing_conjunct(b(member(_,B),_,_)) :- is_just_type(B).
3302 is_typing_predicate(Typing) :- conjunction_to_list(Typing,LT), maplist(is_typing_conjunct,LT).
3303 conjunction_to_nontyping_list(Pred,List) :- conjunction_to_list(Pred,TList), exclude(is_typing_conjunct,TList,List).
3304
3305 % used e.g. for translating : ran({x1,...xn|P}) --> {xn| #(x1,...).(P)}
3306 % we annotate this exists as allow_to_lift; as the origin is a set comprehension which originally had all variables at the top-level (including the existentially quantified ones)
3307 create_outer_exists_for_dom_range(Ids,CompPred,NewCompPred) :-
3308 create_outer_exists_for_dom_range2(Ids,CompPred,NewCompPred1),
3309 compute_used_ids_info_if_necessary(NewCompPred1,NewCompPred).
3310 create_outer_exists_for_dom_range2(Ids,b(exists(InnerIds,P),pred,Infos),New) :-
3311 ? member(allow_to_lift_exists,Infos),
3312 append(Ids,InnerIds,NewIds),!, % simply add Ids to existing existential quantifier
3313 New = b(exists(NewIds,P),pred,NewInfos),
3314 remove_from_used_ids(Infos,Ids,NewInfos).
3315 create_outer_exists_for_dom_range2(Ids,P,New) :-
3316 % we could also use construct_optimized_exists/3 it does a full partitioning of P; see also components_partition_exists rule above
3317 create_exists_opt_liftable(Ids,P,New). % marked as liftable as origin is a set comprehension with all ids
3318 % calls create_exists_opt: detects also simple tautologies like #x.(x=E)
3319 % + predicates that do not use one of the quantified identifiers are moved outside
3320 %N=b(P2,T2,[allow_to_lift_exists|I2]). %, check_ast(N).
3321
3322 % remove newly quantified Typed IDs from used_ids info; if the info exists
3323 remove_from_used_ids(OldInfo,NewQuantifiedTIds,NewInfo) :-
3324 ? select(used_ids(OldUsed),OldInfo,I1),!,
3325 get_texpr_ids(NewQuantifiedTIds,NewQ),
3326 NewInfo = [used_ids(NewUsed)|I1],
3327 ord_subtract(OldUsed,NewQ,NewUsed).
3328 remove_from_used_ids(I,_,I).
3329
3330 % if _lambda_result_ occurs in list; rename it so that we do not get issues with enumeration
3331 rename_lambda_result_id(Ids,CompPred,NewIds,NewCompPred) :-
3332 ? select(ID,Ids,Rest),
3333 get_texpr_id(ID,'_lambda_result_'),
3334 !,
3335 get_unique_id_inside('__RANGE_LAMBDA__',CompPred,FRESHID), % if we don't rename then _lambda_result_ will not be enumerated ! TO DO: also check different from Ids if we want to remove __ prefix
3336 % TO DO: remove lambda_result(Info)
3337 ? rename_bt(CompPred,[rename('_lambda_result_',FRESHID)],NewCompPred),
3338 get_texpr_type(ID,IDType), get_texpr_info(ID,IDInfo),
3339 NewIds = [b(identifier(FRESHID),IDType,IDInfo)|Rest].
3340 rename_lambda_result_id(Ids,CompPred,Ids,CompPred).
3341
3342 contains_predicate(convert_bool(Pred),boolean,Pred,
3343 convert_bool(NewP),NewP).
3344 contains_predicate(comprehension_set(CompIds,Pred),_,Pred,
3345 comprehension_set(CompIds,NewP),NewP).
3346 contains_predicate(general_sum(Ids,Pred,Expression),integer,Pred,
3347 general_sum(Ids,NewP,Expression),NewP).
3348 contains_predicate(general_product(Ids,Pred,Expression),integer,Pred,
3349 general_product(Ids,NewP,Expression),NewP).
3350 contains_predicate(if_then_else(Pred,Then,Else),_,Pred,
3351 if_then_else(NewP,Then,Else),NewP).
3352 contains_predicate(assertion_expression(Pred,ErrMsg,Expr),_,Pred,
3353 assertion_expression(NewP,ErrMsg,Expr),NewP).
3354 contains_predicate(precondition(Pred,Body),subst,Pred,
3355 precondition(NewP,Body),NewP).
3356 contains_predicate(assertion(Pred,Body),subst,Pred,
3357 assertion(NewP,Body),NewP).
3358 contains_predicate(witness_then(Pred,Body),subst,Pred,
3359 witness_then(NewP,Body),NewP).
3360 contains_predicate(becomes_such(Vars,Pred),subst,Pred,
3361 becomes_such(Vars,NewP),NewP).
3362 contains_predicate(any(Parameters,Pred,Body),subst,Pred,
3363 any(Parameters,NewP,Body),NewP).
3364 contains_predicate(lazy_let_expr(ID,SharedExpr,MainExpr),pred, SharedExpr,
3365 lazy_let_expr(ID,NewSharedExpr,MainExpr), NewSharedExpr) :-
3366 get_texpr_type(SharedExpr,pred).
3367 contains_predicate(lazy_let_subst(ID,SharedExpr,MainExpr),pred, SharedExpr,
3368 lazy_let_subst(ID,NewSharedExpr,MainExpr), NewSharedExpr) :-
3369 get_texpr_type(SharedExpr,pred).
3370 contains_predicate(lazy_let_pred(ID,SharedExpr,MainExpr),pred, MainExpr,
3371 lazy_let_pred(ID,SharedExpr,NewMainExpr), NewMainExpr) :-
3372 \+ get_texpr_type(SharedExpr,pred).
3373 % while(COND,STMT,INV,VARIANT), select, if --> can have multiple predicates !!
3374 contains_predicates(while(Cond, Stmt,Invariant,Variant),subst, [Cond,Invariant],
3375 while(NewCond,Stmt,NewInv, Variant), [NewCond,NewInv]).
3376 contains_predicates(if(Whens),subst,Preds,
3377 if(NewWhens),NewPreds) :-
3378 get_predicates_from_list_of_cases(Whens,Preds,NewWhens,NewPreds).
3379 contains_predicates(select(Whens),subst,Preds,
3380 select(NewWhens),NewPreds) :-
3381 get_predicates_from_list_of_cases(Whens,Preds,NewWhens,NewPreds).
3382 contains_predicates(select(Whens,Else),subst,Preds,
3383 select(NewWhens,Else),NewPreds) :-
3384 get_predicates_from_list_of_cases(Whens,Preds,NewWhens,NewPreds).
3385 contains_predicates(lazy_let_pred(ID,SharedExpr,MainExpr),pred, [SharedExpr,MainExpr],
3386 lazy_let_pred(ID,NSharedExpr,NMainExpr), [NSharedExpr,NMainExpr]) :-
3387 get_texpr_type(SharedExpr,pred).
3388
3389 get_predicates_from_list_of_cases([],[],[],[]).
3390 get_predicates_from_list_of_cases([H|T],Preds,[NewH|NewT],NewPreds) :-
3391 (get_single_predicate(H,Pred,NH,NewPred)
3392 -> NewH=NH, Preds=[Pred|TP], NewPreds = [NewPred|NTP]
3393 ; NewH=H, Preds=TP, NewPreds = NTP
3394 ),
3395 get_predicates_from_list_of_cases(T,TP,NewT,NTP).
3396
3397 get_single_predicate(b(E,T,I),Preds,b(NewE,T,I),NewPreds) :-
3398 get_single_predicate_aux(E,Preds,NewE,NewPreds).
3399 get_single_predicate_aux(select_when(Pred,Body),Pred,select_when(NewPred,Body),NewPred).
3400 get_single_predicate_aux(if_elsif(Pred,Body),Pred,if_elsif(NewPred,Body),NewPred).
3401
3402
3403 % Detect useless statements in sequential compositions:
3404 % useful for LCHIP code, e.g., where dummy code is added for the code generator: i9 : (i9 : BOOL); i9 := TRUE
3405 % in test 1660 we remove an assignment that reads an unitialised variable
3406 filter_useless_subst_in_sequence([],_,R) :- !, R=[].
3407 filter_useless_subst_in_sequence([S1],_,R) :- !, R=[S1].
3408 filter_useless_subst_in_sequence([S1|S2],change,R) :- useless_subst_in_sequence(S1,S2),!,
3409 add_hint_message(filter_useless_subst_in_sequence,'Removing useless substitution in sequence','',S1),
3410 filter_useless_subst_in_sequence(S2,_,R).
3411 filter_useless_subst_in_sequence([S1|S2],Change,[S1|RS]) :- filter_useless_subst_in_sequence(S2,Change,RS).
3412
3413 useless_subst_in_sequence(b(Subst,subst,Info),Sequence2) :- % print(check(Subst,Sequence2)),nl,
3414 useless_code_before_sequence(Subst,Info,Sequence2).
3415
3416 useless_code_before_sequence(skip,_,_) :- !.
3417 useless_code_before_sequence(Subst,_,SubstList) :- is_non_failing_assignment(Subst,TID), def_get_texpr_id(TID,ID),
3418 is_dead(ID,SubstList).
3419
3420 % first naive version to compute if the variable ID is dead when followed by a list of substitutions
3421 is_dead(ID,[b(Subst,subst,Info)|_]) :- % we currently only look at first statement; TO DO: improve
3422 is_dead_aux(Subst,Info,ID).
3423 is_dead_aux(assign_single_id(TID,RHS),_Info,ID) :-
3424 get_texpr_id(TID,ID), % we assign to ID; TO DO: deal with other assignments and assignments to functions f(i) := ...
3425 find_identifier_uses_if_necessary(RHS,[],UsedIds),
3426 \+ ord_member(ID,UsedIds).
3427
3428 % non failing assignment without WD condition, note that we may still try and read identifiers that have not been initialised (having term(undefined) as value), see test 1660
3429 is_non_failing_assignment(becomes_such([TID],Pred),TID) :- is_truth(Pred).
3430 is_non_failing_assignment(becomes_element_of([TID],Set),TID) :- definitely_not_empty_set(Set).
3431 is_non_failing_assignment(assign_single_id(TID,RHS),TID) :- always_well_defined_or_disprover_mode(RHS).
3432 is_non_failing_assignment(assign([LHS],[RHS]),TID) :- always_well_defined_or_disprover_mode(RHS),
3433 get_lhs_assigned_identifier(LHS,TID).
3434
3435
3436 % ---------------------------------------------
3437
3438 :- use_module(extrasrc(b_expression_sharing),[cse_optimize_predicate/2]).
3439 % these are "global" optimizations at the predicate level
3440 % they are only called once a predicate has been completely constructed
3441 predicate_level_optimizations(Pred,NewPred) :-
3442 predicate_level_optimizations(Pred,NewPred,[]).
3443 predicate_level_optimizations(Pred,NewPred,Path) :-
3444 inner_predicate_level_optimizations(Pred,Pred1),
3445 (get_preference(use_common_subexpression_elimination,true),
3446 \+ do_not_optimise_in_context(Path)
3447 -> cse_optimize_predicate(Pred1,NewPred)
3448 ; NewPred=Pred1
3449 ). %,print_opt_debug_info(Pred,NewPred,Path).
3450 /*
3451 print_opt_debug_info(Pred,NewPred,Path) :-
3452 (Pred==NewPred -> true
3453 ; same_texpr(Pred,NewPred) -> true
3454 ; format('Optimized pred ~w: ',[Path]), print_bexpr(NewPred),nl
3455 % , (Path=[] -> trace ; true)
3456 ).
3457 */
3458
3459 do_not_optimise_in_context([path_arg(top_level(invariant),Nr)]) :-
3460 get_preference(use_po,true),
3461 debug_format(19,'% NOT applying CSE to Invariant Nr ~w (PROOF_INFO = TRUE)~n',[Nr]).
3462
3463 :- use_module(partition_detection,[detect_all_partitions_in_predicate/2]).
3464 % this predicate is also called for exists, forall, ...:
3465 inner_predicate_level_optimizations(Pred,NewPred) :-
3466 detect_all_partitions_in_predicate(Pred,NewPred1),
3467 (get_preference(remove_implied_constraints,true)
3468 -> remove_implied_constraints(NewPred1,NewPred)
3469 ; NewPred=NewPred1)
3470 . %,(Pred==NewPred -> true ; print('Optimized pred: '), print_bexpr(NewPred),nl).
3471
3472
3473
3474 % ----------------------------------
3475
3476 remove_implied_constraints(Predicate,NewPredicate) :-
3477 conjunction_to_list(Predicate,PList),
3478 remove_implied_constraints(PList,[],PNew),
3479 conjunct_predicates_with_pos_info(PNew,NewPredicate).
3480
3481 % remove constraints which are redundant for ProB
3482 % example:
3483 % n=1000 & f:1..n --> BOOL & f:1..n +-> BOOL & !x.(x:dom(f) => f(x) = bool(x>50)) & f: 1..n <-> BOOL & dom(f)=1..n
3484 % runtime goes from 500 ms down to 300 ms by remove +->, <-> and dom(f) checks
3485 % but test 1442 has issue: still unclear how useful this static detection is
3486 % it is probably most useful for proving/disproving where we have lots of redundant/derived hypotheses
3487
3488 remove_implied_constraints([],_,[]).
3489 remove_implied_constraints([Constraint|T],SoFar,Result) :-
3490 % print('Checking: '), print_bexpr(Constraint),nl,
3491 possible_implied_constraint(Constraint,C1),
3492 % print('Checking if implied constraint: '), print_bexpr(Constraint),nl,
3493 ? (member(TC2,T) ; member(TC2,SoFar)),
3494 get_texpr_expr(TC2,C2),
3495 ? implied_constraint2(C2,C1),
3496 (debug_mode(off) -> true
3497 ; print('Removing implied constraint: '), print_bexpr(Constraint),
3498 print(' <=== '), print_bexpr(TC2),nl),
3499 !,
3500 remove_implied_constraints(T,SoFar,Result).
3501 remove_implied_constraints([H|T],SoFar,[H|RT]) :- remove_implied_constraints(T,[H|SoFar],RT).
3502
3503 possible_implied_constraint(b(E,T,I),E) :-
3504 (possible_implied_constraint2(E,T,I) -> true).
3505 possible_implied_constraint2(member(_,b(FUNCTION,_,_)),_,_) :- functor(FUNCTION,F,2),
3506 (function_implication2(F,_) -> true ; F = relations).
3507 possible_implied_constraint2(equal(b(domain(_),_,_),_),_,_). % TO DO: other way around
3508
3509 % f: A --> B ==> f: A +-> B, f: A<->B, dom(f) = A
3510 % test 1442: issue with surjection
3511 implied_constraint2(member(Fun1,b(FUNCTION1,T,_)), member(Fun2,b(FUNCTION2,T,_))) :-
3512 functor(FUNCTION1,F1,2), arg(1,FUNCTION1,X1), arg(2,FUNCTION1,Y1),
3513 functor(FUNCTION2,F2,2), arg(1,FUNCTION2,X2), arg(2,FUNCTION2,Y2),
3514 ? function_implication(F1,F2),
3515 same_texpr(Fun1,Fun2),
3516 same_texpr(X1,X2),
3517 same_texpr(Y1,Y2).
3518 % f: A --> B ==> dom(f) = A
3519 implied_constraint2(member(Fun2,b(FUNCTION2,_,_)), equal(b(domain(Fun1),_,_),Domain)) :-
3520 functor(FUNCTION2,F2,2), arg(1,FUNCTION2,Domain2),
3521 total_function(F2),
3522 same_texpr(Fun1,Fun2),
3523 same_texpr(Domain,Domain2).
3524 % TODO: f: A -->> B ==> ran(f) = B ?
3525
3526
3527 total_function(total_bijection).
3528 total_function(total_injection).
3529 total_function(total_surjection).
3530 total_function(total_function).
3531 %total_relation(total_surjection_relation). % not sure if in this case the constraint is maybe not useful after all?
3532 %total_relation(total_relation).
3533
3534 function_implication(F1,F2) :- function_implication2(F1,F2).
3535 ?function_implication(F1,F2) :- function_implication2(F1,Z), function_implication(Z,F2).
3536
3537 function_implication2(total_bijection,total_injection).
3538 function_implication2(total_bijection,total_surjection).
3539 function_implication2(total_injection,total_function).
3540 function_implication2(total_surjection,total_function).
3541 function_implication2(total_function,partial_function).
3542 function_implication2(partial_function,relations).
3543 function_implication2(partial_injection,partial_function). % >+>
3544 function_implication2(partial_surjection,partial_function).
3545 %function_implication2(partial_bijection,partial_injection).
3546 %function_implication2(partial_bijection,partial_surjection).
3547 function_implication2(total_relation,relations).
3548 function_implication2(surjection_relation,relations).
3549 function_implication2(total_surjection_relation,total_relation).
3550 function_implication2(total_surjection_relation,surjection_relation).
3551
3552 % ------------------
3553
3554
3555 % divide a list of identifiers into domain and range identifiers
3556 get_domain_range_ids([D,R],[D],[R]) :- !.
3557 get_domain_range_ids([D1,D2|T],[D1|DT],R) :- get_domain_range_ids([D2|T],DT,R).
3558
3559
3560 % detect whether there is a pattern of a recursive usage of the identifier: ID(x) or ID[x] or x:ID
3561 find_recursive_usage(TExpr,ID) :-
3562 syntaxtraversion(TExpr,Expr,_,_,Subs,TNames), % print(try_id(ID,Expr,Subs,TNames)),nl,
3563 ( Expr = function(Fun,_), get_texpr_id(Fun,ID) -> true
3564 ; Expr = image(Rel,_), get_texpr_id(Rel,ID) -> true
3565 ; Expr = member(_,Set), get_texpr_id(Set,ID) -> true
3566 ? ; \+ (member(ID1,TNames),get_texpr_id(ID1,ID)), % new local variable with same name
3567 ? member(Sub,Subs), find_recursive_usage(Sub,ID)
3568 ).
3569
3570 :- use_module(bsyntaxtree,[transform_bexpr/3]).
3571 % find comprehension sets and mark them as recursive if they use the recursive ID
3572 mark_recursion(TExpr,RecID,NewTExpr) :-
3573 (transform_bexpr(b_ast_cleanup:mark_comprehension_set(RecID),TExpr,NewTExpr)
3574 -> true
3575 ; add_internal_error('Call failed: ',transform_bexpr(b_ast_cleanup:mark_comprehension_set(RecID),TExpr,NewTExpr)),
3576 NewTExpr=TExpr).
3577
3578 :- public mark_comprehension_set/3.
3579 mark_comprehension_set(RecID,b(lambda(Ids,P,Expr),Type,Info),
3580 b(lambda(Ids,P,Expr),Type,NInfo)) :-
3581 (find_recursive_usage(P,RecID) -> true ; find_recursive_usage(Expr,RecID)),
3582 get_texpr_ids(Ids,AtomicIds),
3583 (silent_mode(on) -> true
3584 ; format('Recursive lambda using ~w detected (name: ~w)~n',[AtomicIds,RecID]),
3585 error_manager:print_message_span(Info),nl
3586 ),
3587 add_texpr_infos(Info,[prob_annotation('SYMBOLIC'),prob_annotation('RECURSIVE')],NInfo).
3588 mark_comprehension_set(RecID,b(comprehension_set(Ids,P),Type,Info),
3589 b(comprehension_set(Ids,P),Type,NInfo)) :-
3590 % DO NOT MARK IT IF IT IS IN RESULT POSITION of recursive function ?
3591 ? find_recursive_usage(P,RecID),
3592 get_texpr_ids(Ids,AtomicIds),
3593 (silent_mode(on) -> true
3594 ; format('Recursive comprehension set using ~w detected (name: ~w)~n',[AtomicIds,RecID]),
3595 error_manager:print_message_span(Info),nl
3596 ),
3597 NInfo = [prob_annotation('SYMBOLIC'),prob_annotation('RECURSIVE')|Info]. % TO DO: only add if not already there
3598
3599 mark_comprehension_set_with(b(X,Type,I),ANN,b(X2,Type,I2)) :- % ANN = 'SYMBOLIC' or 'FORCE' or ...
3600 (X=comprehension_set(Ids,b(P,pred,IP))
3601 -> X2 = comprehension_set(Ids,b(P,pred,IP2)), I2=I,
3602 add_info_if_new(IP,prob_annotation(ANN),IP2)
3603 ; X2=X, add_info_if_new(I,prob_annotation(ANN),I2)
3604 ).
3605
3606 % pred(h) --> h-1, succ(h) --> h+1
3607 precompute_pred_succ_function_call(Fun,Arg,ArithOp) :-
3608 get_texpr_expr(Fun,PS),
3609 ( PS=predecessor -> Op=minus
3610 ; PS=successor -> Op=add), % we could use add_one predicate
3611 ArithOp =.. [Op,Arg,Integer],
3612 create_texpr(integer(1),integer,[],Integer).
3613
3614 %
3615 one(b(integer(1),integer,[])).
3616 create_interval_member(X,LowBound,UpBound,Member) :-
3617 safe_create_texpr(interval(LowBound,UpBound),set(integer),Interval),
3618 safe_create_texpr(member(X,Interval),pred,Member).
3619
3620 get_leq_comparison(less(A,B),A,B1) :- minus_one(B,BM1),
3621 safe_create_texpr(BM1,integer,B1).
3622 get_leq_comparison(greater(B,A),A,B1) :- get_leq_comparison(less(A,B),A,B1).
3623 get_leq_comparison(less_equal(A,B),A,B).
3624 get_leq_comparison(greater_equal(B,A),A,B).
3625
3626 minus_one(b(integer(I),integer,_),Res) :- !, I1 is I-1, Res=integer(I1).
3627 minus_one(B,minus(B,One)) :- one(One).
3628 add_one(b(integer(I),integer,_),Res) :- !, I1 is I+1, Res=integer(I1).
3629 add_one(B,add(B,One)) :- one(One).
3630
3631 % get_geq_comparison(Expr,LHS,RHS) ; RHS can be shifted by 1
3632 get_geq_comparison(less(B,A),A,B1) :- get_geq_comparison(greater(A,B),A,B1).
3633 get_geq_comparison(greater(A,B),A,B1) :- add_one(B,BP1),
3634 safe_create_texpr(BP1,integer,B1).
3635 get_geq_comparison(less_equal(B,A),A,B).
3636 get_geq_comparison(greater_equal(A,B),A,B).
3637 get_geq_comparison(member(A,SET),A,b(integer(Bound),integer,[])) :-
3638 is_inf_integer_set_with_lower_bound(SET,Bound).
3639 % comparison operators:
3640 comparison(equal(A,B),A,B,equal(SA,SB),SA,SB).
3641 comparison(not_equal(A,B),A,B,not_equal(SA,SB),SA,SB).
3642 comparison(greater(A,B),A,B,greater(SA,SB),SA,SB).
3643 comparison(less(A,B),A,B,less(SA,SB),SA,SB).
3644 comparison(greater_equal(A,B),A,B,greater_equal(SA,SB),SA,SB).
3645 comparison(less_equal(A,B),A,B,less_equal(SA,SB),SA,SB).
3646 % rules to simplify binary comparison arguments
3647 simplify_comparison_terms(b(A,T,_IA),b(B,T,_IB),RA,RB) :-
3648 simplify_comparison_terms2(A,B,RA,RB).
3649 % TO DO: expand into much better simplifier !
3650 simplify_comparison_terms2(minus(A1,A2),minus(B1,B2),ResA,ResB) :-
3651 ( same_texpr(A1,B1) -> ResA=B2, ResB=A2 % X-A2 < X-B2 <=> B2 < A2
3652 ; same_texpr(A2,B2) -> ResA=A1, ResB=B1). % A1-X < B1-X <=> A1 < B1
3653 simplify_comparison_terms2(add(A1,A2),add(B1,B2),ResA,ResB) :-
3654 ( same_texpr(A1,B1) -> ResA=A2, ResB=B2 % X+A2 < X+B2 <=> A2 < B2
3655 ; same_texpr(A2,B2) -> ResA=A1, ResB=B1 % A1+X < B1+X <=> A1 < B1
3656 ; same_texpr(A1,B2) -> ResA=A2, ResB=B1 % X+A2 < B1+X <=> A2 < B1
3657 ; same_texpr(A2,B1) -> ResA=A1, ResB=B2). % A1+X < X+B2 <=> A1 < B2
3658 % multiplication: beware of sign, same with division
3659
3660
3661
3662 % simplify equality/inequality Unifications:
3663 simplify_equality(b(A,T,_),b(B,T,_),A2,B2) :-
3664 simplify_equality_aux(A,B,T,A2,B2).
3665 simplify_equality_aux(set_extension([A1]),set_extension([B1]),_,A2,B2) :- !,
3666 opt_simplify_equality(A1,B1,A2,B2).
3667 simplify_equality_aux(CoupleA,Type,CoupleB,A3,B3) :-
3668 get_couple(CoupleA,Type,A1,A2),
3669 get_couple(CoupleB,Type,B1,B2),
3670 (same_texpr(A1,B1), % (1,x)=(1,3) -> x=3
3671 always_well_defined_or_disprover_mode(A1)
3672 -> opt_simplify_equality(A2,B2,A3,B3)
3673 ; same_texpr(A2,B2),always_well_defined_or_disprover_mode(A2)
3674 -> opt_simplify_equality(A1,B1,A3,B3)
3675 ; different_texpr_values(A1,B1), % (1,x)=(2,3) -> 1=2
3676 always_well_defined_or_wd_improvements_allowed(A2),
3677 always_well_defined_or_wd_improvements_allowed(B2)
3678 -> (A3,B3) = (A1,B1) % no need to compare A2,B2
3679 ; different_texpr_values(A2,B2), always_well_defined_or_wd_improvements_allowed(A1),
3680 always_well_defined_or_wd_improvements_allowed(B1)
3681 -> (A3,B3) = (A2,B2) % no need to compare A1,B1
3682 ).
3683
3684 % flexibly get a couple from either AST or value:
3685 get_couple(couple(A1,A2),_,A1,A2).
3686 get_couple(value(CVal),couple(T1,T2),A1,A2) :- nonvar(CVal), CVal=(V1,V2),
3687 A1=b(value(V1),T1,[]), A2=b(value(V2),T2,[]).
3688
3689 opt_simplify_equality(A1,B1,A2,B2) :-
3690 (simplify_equality(A1,B1,A2,B2) -> true ; A2=A1, B2=B1).
3691
3692 % record field set extraction:
3693 construct_field_sets(FieldsSetsOut, field(Name,Type), field(Name,NewSet)) :-
3694 ? (member(field_set(Name,NewSet),FieldsSetsOut)
3695 -> true
3696 ; create_maximal_type_set(Type,NewSet)
3697 ).
3698
3699 % traverse a list of conjuncts and check that they all restrict fields of a record ID
3700 % all sets are combined via intersection
3701 l_update_record_field_membership([],_) --> [].
3702 l_update_record_field_membership([H|T],ID) -->
3703 update_record_field_membership(H,ID), l_update_record_field_membership(T,ID).
3704 update_record_field_membership(b(member(b(LHS,_,_),TRHS),pred,_),ID) --> update2(LHS,TRHS,ID).
3705 update2(record_field(RECID,FieldName),TRHS,ID) --> {get_texpr_id(RECID,ID)},add_field_restriction(FieldName,TRHS).
3706 update2(identifier(ID),b(struct(b(rec(FieldSets),_,_)),_,_),ID) -->
3707 l_add_field_restriction(FieldSets).
3708
3709 l_add_field_restriction([]) --> [].
3710 l_add_field_restriction([field(FieldName,TRHS)|T]) -->
3711 add_field_restriction(FieldName,TRHS), l_add_field_restriction(T).
3712 add_field_restriction(FieldName,TRHS,FieldsIn,FieldsOut) :-
3713 ? (select(field_set(FieldName,OldSet),FieldsIn,F2)
3714 -> OldSet = b(_,Type,_),
3715 safe_create_texpr(intersection(OldSet,TRHS),Type,NewSet),
3716 FieldsOut = [field_set(FieldName,NewSet)|F2]
3717 ; FieldsOut = [field_set(FieldName,TRHS)|FieldsIn]).
3718 % end record field extraction
3719
3720
3721 extract_unions(A,R) :- get_texpr_expr(A,union(A1,A2)),!,
3722 extract_unions(A1,R1), extract_unions(A2,R2),
3723 append(R1,R2,R).
3724 extract_unions(A,[A]).
3725
3726 gen_member_predicates(B,SEl,TExpr) :- safe_create_texpr(member(SEl,B),pred,TExpr).
3727
3728 % when constructing an expression/predicate: important to ripple wd information up
3729 extract_important_info_from_subexpression(b(_,_,Info),NewInfo) :-
3730 include(important_info_from_sub_expr,Info,NewInfo).
3731
3732 extract_important_info_from_subexpressions(b(_,_,Info1),b(_,_,Info2),NewInfo) :-
3733 include(important_info_from_sub_expr,Info1,II1),
3734 (memberchk(contains_wd_condition,Info2), nonmember(contains_wd_condition,II1)
3735 -> NewInfo = [contains_wd_condition|II1]
3736 ; NewInfo=II1). % TO DO: maybe also import other Infos? merge position info (nodeid(_))?
3737 % other important ones: removed_typing ??
3738
3739 % include important info from removed conjunct (note: see also extract_info in bsyntaxtree)
3740 % include_important_info(RemovedPredInfo,RemainingPredInfo,NewInfo)
3741 include_important_info_from_removed_pred([],Info2,Info2).
3742 include_important_info_from_removed_pred([H1|Info1],Info2,NewInfo2) :-
3743 (is_removed_typing_info(H1), nonmember(removed_typing,Info2)
3744 -> NewInfo2 = [removed_typing|Info2]
3745 ; include_important_info_from_removed_pred(Info1,Info2,NewInfo2)).
3746
3747 is_removed_typing_info(was(_)).
3748 is_removed_typing_info(removed_typing).
3749
3750 important_info_from_sub_expr(removed_typing).
3751 important_info_from_sub_expr(contains_wd_condition).
3752 important_info_from_sub_expr(prob_annotation(_)).
3753 important_info_from_sub_expr(nodeid(_)).
3754 important_info_from_sub_expr(was(_)).
3755 %important_info(allow_to_lift_exists). % important but only for exists; should not be copied to outer predicates
3756
3757 % add important infos in case an expression gets simplified into a sub-expression, e.g., bool(X)=TRUE -> X
3758 add_important_info_from_super_expression(Infos,SubInfos,NewSubInfos) :-
3759 include(important_info_from_super_expression,Infos,Important), % print(add_important(Important)),nl,
3760 add_infos_if_new(Important,SubInfos,NewSubInfos).
3761
3762
3763 important_info_from_super_expression(label(_)).
3764 important_info_from_super_expression(P) :- is_rodin_label_info(P). % important for Rodin proof info; if an invariant is partioned
3765 %add_important_info_to_texpr_from_super(Infos,b(Sub,T,SubInfos),b(Sub,T,NewSubInfos)) :- !,
3766 % add_important_info_from_super_expression(Infos,SubInfos,NewSubInfos).
3767
3768 important_info_for_exists(allow_to_lift_exists).
3769 ?important_info_for_exists(Label) :- important_info_from_super_expression(Label).
3770 % add important infos to individual conjuncts which are exists constructs; used when partitioning of exists:
3771 add_important_infos_to_exists_conjuncts(TPred,SuperInfos,SuperIds,NewTPred) :-
3772 include(important_info_for_exists,SuperInfos,Important),
3773 (Important=[]
3774 -> NewTPred=TPred
3775 ; add_to_conjuncts_aux(TPred,Important,SuperIds,NewTPred)
3776 ).
3777 add_to_conjuncts_aux(b(Pred,Type,Infos),Important,SuperIds,b(NP,Type,NewSubInfos)) :-
3778 (Pred=conjunct(A,B)
3779 -> NP=conjunct(NA,NB), NewSubInfos=Infos,
3780 add_to_conjuncts_aux(A,Important,SuperIds,NA),
3781 add_to_conjuncts_aux(B,Important,SuperIds,NB)
3782 ? ; Pred=exists(InnerIds,_), member(TID,InnerIds),
3783 def_get_texpr_id(TID,ID),
3784 ord_member(ID,SuperIds) % the exists is probably related to the outer exists
3785 % (TODO: it could be a lifted clashing one: perform this annotation directly in construct_optimized_exists !!)
3786 -> append(Important,Infos,NewSubInfos), % copy infos from original exists
3787 NP=Pred
3788 ; NP=Pred, NewSubInfos=Infos).
3789
3790 % extract all assignments from a list of statements; last arg is the number of assignments extracted
3791 extract_assignments([],[],[],[],0).
3792 extract_assignments([H|T],ResLHS,ResRHS,Rest,Nr) :-
3793 is_ordinary_assignment(H,LHS,RHS,Cnt),!,
3794 extract_assignments(T,LT,RT,Rest,N),
3795 append(LHS,LT,ResLHS), append(RHS,RT,ResRHS), Nr is N+Cnt.
3796 extract_assignments([H|T],LT,RT,[H|Rest],Nr) :-
3797 extract_assignments(T,LT,RT,Rest,Nr).
3798 % assigned_after(Primed),modifies(Var)
3799
3800 % check if we have an ordinary assignment that can be merged, optimised:
3801 is_ordinary_assignment(b(S,_,Info),LHS,RHS,Cnt) :- is_ordinary_assignment_aux(S,Info,LHS,RHS,Cnt).
3802 is_ordinary_assignment_aux(skip,_Info,[],[],0).
3803 is_ordinary_assignment_aux(assign_single_id(LHS,RHS),_Info,[LHS],[RHS],0). % count=0: used for parallel merge: assign_single_id less useful to merge with
3804 is_ordinary_assignment_aux(assign(LHS,RHS),Info,LHS,RHS,1) :-
3805 \+ member(assigned_after(_),Info), % these assignments are treated in a special way
3806 \+ member(modifies(_),Info).
3807
3808 % merge assignments in a list of statements to be executed by sequential composition:
3809 merge_assignments([S1,S2|T],merged,Res) :- merge_two_assignments(S1,S2,New),!,
3810 merge_assignments([New|T],_,Res).
3811 merge_assignments([],no_merge,[]).
3812 merge_assignments([H|T],Merge,[H|TR]) :- merge_assignments(T,Merge,TR).
3813
3814 :- use_module(b_read_write_info,[get_lhs_assigned_identifier/2]).
3815 get_lhs_assigned_ids(LHS,SortedIds) :-
3816 maplist(get_lhs_assigned_identifier,LHS,TLHSAssign),
3817 get_sorted_ids(TLHSAssign,SortedIds).
3818 merge_two_assignments(S1,S2,NewAssignment) :-
3819 is_ordinary_assignment(S1,LHS1,RHS1,_),
3820 is_ordinary_assignment(S2,LHS2,RHS2,_),
3821 get_lhs_assigned_ids(LHS1,SortedIDs1),
3822 get_lhs_assigned_ids(LHS2,SortedIDs2),
3823 ord_disjoint(SortedIDs1,SortedIDs2), % no race condition
3824 maplist(not_occurs_in_predicate(SortedIDs1),RHS2),
3825 maplist(not_occurs_in_predicate(SortedIDs1),LHS2), % not used in left-hand side, e.g., f(x+y) := RHS
3826 get_texpr_info(S1,I1), get_texpr_info(S2,I2),
3827 merge_info(I1,I2,Infos),
3828 append(LHS1,LHS2,NewLHS),
3829 append(RHS1,RHS2,NewRHS),
3830 NewAssignment = b(assign(NewLHS,NewRHS),subst,Infos),
3831 (debug_mode(off) -> true ; print('Merged assignments: '),translate:print_subst(NewAssignment),nl).
3832 construct_sequence([],skip).
3833 construct_sequence([TH],H) :- !, TH=b(H,_,_).
3834 construct_sequence(List,sequence(List)).
3835
3836 % check if we have a simple expression which will not be complicated to calculate
3837 ?simple_expression(b(E,_,_)) :- simple2(E).
3838 % (simple2(E) -> true ; print(not_simple(E)),nl).
3839 simple2(bool_set).
3840 simple2(boolean_false).
3841 simple2(boolean_true).
3842 simple2(empty_sequence).
3843 simple2(empty_set).
3844 simple2(identifier(_)).
3845 %simple2(integer_set(_)).
3846 simple2(integer(_)).
3847 simple2(lazy_lookup_expr(_)).
3848 simple2(lazy_let_expr(_,A,B)) :- simple2(B), simple_expr_or_pred(A).
3849 simple2(max_int).
3850 simple2(min_int).
3851 simple2(real_set).
3852 simple2(real(_)).
3853 simple2(string_set).
3854 simple2(string(_)).
3855 simple2(value(_)).
3856 simple2(first_of_pair(_)). simple2(second_of_pair(_)).
3857 ?simple2(couple(A,B)) :- simple_expression(A), simple_expression(B).
3858 ?simple2(interval(A,B)) :- simple_expression(A), simple_expression(B).
3859 ?simple2(add(A,B)) :- simple_expression(A), simple_expression(B).
3860 ?simple2(minus(A,B)) :- simple_expression(A), simple_expression(B).
3861 ?simple2(multiplication(A,B)) :- simple_expression(A), simple_expression(B).
3862 simple2(unary_minus(A)) :- simple_expression(A).
3863 ?simple2(convert_bool(A)) :- simple_predicate(A).
3864 ?simple2(sequence_extension(A)) :- maplist(simple_expression,A).
3865 ?simple2(set_extension(A)) :- maplist(simple_expression,A). % a bit more expensive than sequence_extension: elements need to be compared
3866 simple2(X) :- is_integer_set(X,_).
3867
3868 simple_expr_or_pred(b(E,T,_)) :- (T=pred -> simplep2(E) ; simple2(E)).
3869
3870 ?simple_predicate(b(E,_,_)) :- simplep2(E).
3871 ?simplep2(equal(A,B)) :- simple_expression(A), simple_expression(B). % could be slightly more expensive if set type
3872 ?simplep2(not_equal(A,B)) :- simple_expression(A), simple_expression(B). % ditto
3873 simplep2(lazy_let_pred(_,A,B)) :- simple_predicate(B), simple_expr_or_pred(A).
3874 ?simplep2(less(A,B)) :- simple_expression(A), simple_expression(B).
3875 ?simplep2(less_equal(A,B)) :- simple_expression(A), simple_expression(B).
3876 simplep2(greater(A,B)) :- simple_expression(A), simple_expression(B).
3877 simplep2(greater_equal(A,B)) :- simple_expression(A), simple_expression(B).
3878
3879 % detect ID = Expr or Expr = ID
3880 identifier_equality(TExpr,ID,TID,Expr) :- is_equality(TExpr,LHS,RHS),
3881 ( get_texpr_id(LHS,ID), TID=LHS, Expr = RHS
3882 ; get_texpr_id(RHS,ID), TID=RHS, Expr = LHS).
3883
3884
3885 ?id_member_of_set_extension(TExpr,ID,TID,[Expr]) :- identifier_equality(TExpr,ID,TID,Expr).
3886 id_member_of_set_extension(b(member(TID,SEXT),pred,_),ID,TID,SList) :- get_texpr_id(TID,ID),
3887 is_set_extension(SEXT,SList).
3888
3889 % check if merging disjunctions of set_extensionts of this type is useful in CLP(FD) mode
3890 % see get_fd_type in clpfd_tables, ...
3891 type_contains_fd_index(V) :- var(V),!,fail.
3892 type_contains_fd_index(couple(A,_)) :- type_contains_fd_index(A).
3893 type_contains_fd_index(record([field(_,T1)|_])) :- type_contains_fd_index(T1).
3894 type_contains_fd_index(global(_)).
3895 type_contains_fd_index(integer).
3896 type_contains_fd_index(boolean).
3897
3898
3899 create_equalities_for_let(ORefs,Primed,Equalities) :-
3900 maplist(create_equality_for_let,ORefs,Primed,Equalities).
3901 create_equality_for_let(oref(PrimedId,OrigId,Type),TPrimed,Equality) :-
3902 create_texpr(identifier(OrigId),Type,[],TOrig),
3903 create_texpr(identifier(PrimedId),Type,[],TPrimed),
3904 safe_create_texpr(equal(TPrimed,TOrig),pred,Equality).
3905
3906 % inserts a let statement. If the original statement is a precondition or any, the let is moved
3907 % inside the original statement to prevent strange side-effects. This can be used for other,
3908 % non-value changing substitutions as well.
3909 insert_let(TExpr,Ids,P,NTExpr) :-
3910 remove_bt(TExpr,Expr,NewExpr,NTExpr),
3911 move_let_inside(Expr,Old,New,NewExpr),!,
3912 insert_let(Old,Ids,P,New).
3913 insert_let(TExpr,Ids,P,NTExpr) :-
3914 create_texpr(let(Ids,P,TExpr),subst,[],NTExpr).
3915 move_let_inside(precondition(Cond,Old),Old,New,precondition(Cond,New)).
3916 move_let_inside(any(Any,Where,Old),Old,New,any(Any,Where,New)).
3917
3918 % find_one_point_rules(+TypedIds,+Blacklist,+Predicates,
3919 % -LetIds,-LetExprs,-RemainingIds,-RemainingPredicates)
3920 % TypedIds: The ids that are quantified in the exists clause
3921 % Blacklist: All ids that must not be used in the found expression
3922 % Predicates: The predicates of the exists (without already used id=E predicates)
3923 % LetIds: The ids that can be introduced as LET
3924 % LetExprs. For each id (in LetIds) the corresponding expression
3925 % RemainingIds: The ids that are not converted into LETs
3926 % RemainingPredicates: The predicates after removing the id=E predicates
3927 % (e.g., f = {1|->2} & !e.(2:dom(f) & e=f(2) => e>100) should not generate a WD-error)
3928 find_one_point_rules(TIds,Preds,Blacklist,LetIds,Exprs,RestIds,NewPreds) :-
3929 typed_ids_to_avl(TIds,AVL),
3930 find_one_point_equalities(Preds,is_leftmost,AVL,Blacklist,LetIds,Exprs,RestIds,NewPreds).
3931
3932 :- use_module(library(avl),[avl_range/2, avl_fetch/3, avl_delete/4, empty_avl/1]).
3933 :- use_module(bsyntaxtree,[is_equality/3]).
3934 find_one_point_equalities([],_,AVL,_,[],[],RestIds,[]) :-
3935 avl_range(AVL,RestIds).
3936 find_one_point_equalities([TEqual|TPreds],WDLEFT,AVL,Blacklist,LetIds,Exprs,RestIds,NewPreds) :-
3937 split_equality(TEqual,TEq1,TEq2),
3938 %print('Splitting equality: '), translate:print_bexpr(TEqual),nl,
3939 !,
3940 find_one_point_equalities([TEq1,TEq2|TPreds],WDLEFT,AVL,Blacklist,LetIds,Exprs,RestIds,NewPreds).
3941 find_one_point_equalities([TEqual|TPreds],WDLEFT,AVL,Blacklist,[LetID|LetIds],[Expr|Exprs],RestIds,NewPreds) :-
3942 is_equality(TEqual,TA,TB),
3943 ( get_texpr_id(TA,Id),TB=Expr ; get_texpr_id(TB,Id),TA=Expr ),
3944 avl_fetch(Id,AVL,LetID), % we have an equality involving a quantified identifier
3945 %print(wdleft(WDLEFT,Id)),nl, print_bexpr(Expr),nl,
3946 (WDLEFT=is_leftmost
3947 -> true % all the expressions to the left of the equality are well-defined
3948 ; always_defined_full_check_or_disprover_mode(Expr)), % we can lift Id=Expr to an outer LET
3949 % example: UNION(x).(1:dom(f) & x=f(1)|{x}) --> do not lift x=f(1) out if f(1) is not WD, see test 2195
3950 find_identifier_uses_if_necessary(Expr,[],UsedIds),
3951 ord_disjoint(Blacklist,UsedIds),
3952 % TODO: what if we have an equality between two quantified ids in the blacklist?
3953 !,
3954 avl_delete(Id,AVL,_,AVL2),
3955 (empty_avl(AVL2) % check if we have found equalities for all ids
3956 -> NewPreds=TPreds, LetIds=[],Exprs=[],RestIds=[]
3957 ; % should we add Id to Blacklist; usually all ids are already in the blacklist
3958 % WDLEFT remains unchanged
3959 update_wd_to_left(WDLEFT,Expr,NewWDLEFT),
3960 find_one_point_equalities(TPreds,NewWDLEFT,AVL2,Blacklist,LetIds,Exprs,RestIds,NewPreds)
3961 ).
3962 find_one_point_equalities([TEqual|TPreds],_WDLEFT,AVL,Blacklist,LetIds,Exprs,RestIds,[TEqual|NewPreds]) :-
3963 %update_wd_to_left(WDLEFT,Expr,NewWDLEFT),
3964 find_one_point_equalities(TPreds,not_leftmost,AVL,Blacklist,LetIds,Exprs,RestIds,NewPreds).
3965
3966 % update information about whether the next conjunct should still be considered as leftmost concerning WD
3967 update_wd_to_left(is_leftmost,Expr,NewWD) :- always_defined_full_check_or_disprover_mode(Expr),!,
3968 NewWD = is_leftmost.
3969 update_wd_to_left(_,_,not_leftmost).
3970
3971
3972 :- use_module(library(avl),[list_to_avl/2]).
3973 get_avl_aux(TID,Id-TID) :- get_texpr_id(TID,Id).
3974
3975 % convert an unsorted typed identifier list to an AVL tree
3976 typed_ids_to_avl(TIds,AVL) :-
3977 maplist(get_avl_aux,TIds,L),
3978 list_to_avl(L,AVL).
3979
3980
3981 % select a predicate from Preds of the form id=Expr (or Expr=id) where Expr does not contain
3982 % references to identifiers in Blacklist. Rest is Preds without id=Expr
3983 select_equality(TId,Preds,Blacklist,TEqual,Expr,Rest,UsedIds,CheckWellDef) :-
3984 get_texpr_id(TId,Id),
3985 ? safe_select(CheckWellDef,TEqual,Preds,Rest),
3986 is_equality(TEqual,TA,TB), % the ast_cleanup rules have not run yet on the sub-expressions of the exists: detect more equalities
3987 ( get_texpr_id(TA,Id),TB=Expr ; get_texpr_id(TB,Id),TA=Expr ),
3988 find_identifier_uses_if_necessary(Expr,[],UsedIds),
3989 ord_disjoint(Blacklist,UsedIds).
3990
3991
3992 % safely select a predicate from List, preserving WD (well-definedness)
3993 safe_select(check_well_definedness,Element,[H|T],Rest) :- !,
3994 (Element=H,Rest=T % either first element
3995 ; % or if later element; then it must be well-defined; otherwise H could fail
3996 ? select(Element,T,TRest), Rest=[H|TRest],
3997 always_defined_full_check_or_disprover_mode(Element) % we cannot use always_well_defined(Element) in cleanup_pre; it is only computed in cleanup_post at the moment; TO DO: we now do compute in pre phase
3998 %, print(always_wd(Element)),nl
3999 ).
4000 ?safe_select(_,Element,List,Rest) :- select(Element,List,Rest).
4001
4002 % split predicate list into conjuncts using a certain list of ids and those not
4003 split_predicates(LP,Ids,UsingIds,NotUsingIds) :-
4004 get_sorted_ids(Ids,SIds),
4005 ? filter(not_occurs_in_predicate(SIds),LP,NP,UP),
4006 conjunct_predicates_with_pos_info(NP,NotUsingIds),
4007 conjunct_predicates_with_pos_info(UP,UsingIds).
4008
4009 not_occurs_in_predicate([],_Pred) :- !.
4010 not_occurs_in_predicate(SortedIDs,Pred) :- SortedIDs = [ID1|_],
4011 (ID1 = b(_,_,_) -> add_internal_error('Wrapped identifiers: ',not_occurs_in_predicate(SortedIDs,Pred)) ; true),
4012 find_identifier_uses_if_necessary(Pred,[],UsedIds),
4013 ord_disjoint(SortedIDs,UsedIds).
4014 get_sorted_ids(Ids,SIds) :-
4015 get_texpr_ids(Ids,UnsortedIds),sort(UnsortedIds,SIds).
4016
4017 pred_succ_compset(Op,comprehension_set([A,B],Pred)) :-
4018 %get_unique_id('_a_',AId),get_unique_id('_b_',BId),
4019 BId = '_lambda_result_',
4020 (Op = add -> AId = '_succ_' ; AId='_pred_'),
4021 create_texpr(identifier(AId),integer,[],A),
4022 create_texpr(identifier(BId),integer,[lambda_result(BId)],B),
4023 create_texpr(integer(1),integer,[],Integer),
4024 create_texpr(ArithOp,integer,[],TArithOp),
4025 ArithOp =.. [Op,A,Integer],
4026 safe_create_texpr(equal(B,TArithOp),pred,[prob_annotation('LAMBDA-EQUALITY')],Pred).
4027
4028 add_used_identifier_info(_Ids,_P,IOld,INew) :-
4029 ? member(used_ids(_),IOld),!,INew=IOld.
4030 add_used_identifier_info(Ids,P,IOld,[used_ids(FoundIds)|IOld]) :-
4031 % add used identifiers to information
4032 get_sorted_ids(Ids,Ignore),
4033 find_identifier_uses(P,Ignore,FoundIds).
4034
4035 add_used_ids_defined_by_equality(_Ids,P,IOld,INew) :-
4036 ? member(used_ids(UsedIds),IOld),!,
4037 findall(ID, (member_in_conjunction(Equality,P),
4038 identifier_equality(Equality,ID,_TID,Expr),
4039 ord_member(ID,UsedIds),
4040 not_occurs_in_expr(ID,Expr)), % TO DO: we could check also other ids defined by equality already found
4041 IdsDefinedByEquality),
4042 ? (select(used_ids_defined_by_equality(_),IOld,I1) -> true ; I1=IOld),
4043 (IdsDefinedByEquality=[] -> INew=I1
4044 ; %debug_println(9,used_ids_defined_by_equality(IdsDefinedByEquality)),
4045 INew = [used_ids_defined_by_equality(IdsDefinedByEquality)|I1]
4046 ).
4047 add_used_ids_defined_by_equality(Ids,P,IOld,INew) :-
4048 add_internal_error('No used_ids info:',add_used_ids_defined_by_equality(Ids,P,IOld,INew)),
4049 INew=IOld.
4050
4051
4052 % can be used to check the validity of the used_ids field, e.g., for existential quantifier
4053 check_used_ids_info(Parameters,Predicate,StoredUsedIds,PP) :-
4054 % get_global_identifiers(Ignored), and add to Parameters ??
4055 (add_used_identifier_info(Parameters,Predicate,[],[used_ids(UsedIds)])
4056 -> (StoredUsedIds=UsedIds -> true
4057 ; ord_subset(UsedIds,StoredUsedIds)
4058 -> format('Suboptimal used_ids info: ~w (actual ~w) [origin ~w with ~w]~n',[StoredUsedIds,UsedIds,PP,Parameters])
4059 %, print_bexpr(Predicate),nl
4060 ; add_internal_error('Incorrect used_ids info: ', check_used_ids_info(Parameters,Predicate,UsedIds,PP)),
4061 print_bexpr(Predicate),nl,
4062 (extract_span_description(Predicate,PosMsg) -> format('Location: ~w~n',[PosMsg]) ; true),
4063 ord_subtract(UsedIds,StoredUsedIds,Delta),
4064 format('Incorrect used_ids info: ~w (actual ~w)~nNot included: ~w~n~n',[StoredUsedIds,UsedIds,Delta])
4065 %, print_bexpr(Predicate),nl
4066 )
4067 ; add_internal_error('Could not computed used ids:',
4068 add_used_identifier_info(Parameters,Predicate,[],[used_ids(_)]))
4069 ).
4070
4071 % update used_ids_info for existential and universal quantifier (at top-level only !)
4072 recompute_used_ids_info(b(E,pred,Info0),Res) :-
4073 delete(Info0,used_ids(_),Info1),
4074 recompute_used_ids_info_aux(E,Info1,Info2),!, Res= b(E,pred,Info2).
4075 recompute_used_ids_info(TE,TE).
4076
4077 compute_used_ids_info_if_necessary(b(E,pred,Info1),Res) :-
4078 recompute_used_ids_info_aux(E,Info1,Info2),!, Res= b(E,pred,Info2).
4079 compute_used_ids_info_if_necessary(TE,TE).
4080
4081 recompute_used_ids_info_aux(exists(Parameters,Predicate),Info1,Info2) :-
4082 add_used_identifier_info(Parameters,Predicate,Info1,Info2).
4083 recompute_used_ids_info_aux(forall(Parameters,Lhs,Rhs),Info1,Info2) :-
4084 conjunct_predicates([Lhs,Rhs],Predicate),
4085 add_used_identifier_info(Parameters,Predicate,Info1,Info2).
4086 % for while loop we could recompute modifies and reads info
4087
4088 % generation of unique identifiers
4089 :- dynamic unique_id_counter/1.
4090 unique_id_counter(1).
4091
4092 get_unique_id_inside(Prefix,Pred,ResultId) :-
4093 (\+ occurs_in_expr(Prefix,Pred) % first try and see whether we need to append a number
4094 -> ResultId = Prefix
4095 ; get_unique_id(Prefix,ResultId)
4096 ).
4097 get_unique_id_inside(Prefix,Pred,Expr,ResultId) :-
4098 ( \+ occurs_in_expr(Prefix,Pred),
4099 \+ occurs_in_expr(Prefix,Expr) % first try and see whether we need to append a number
4100 -> ResultId = Prefix
4101 ; get_unique_id(Prefix,ResultId)
4102 ).
4103
4104 get_unique_id(Prefix,Id) :-
4105 retract(unique_id_counter(Old)),
4106 New is Old + 1,
4107 assertz(unique_id_counter(New)),
4108 safe_atom_chars(Prefix,CPrefix,get_unique_id1),
4109 number_chars(Old,CNumber),
4110 append(CPrefix,CNumber,CId),
4111 safe_atom_chars(Id,CId,get_unique_id2).
4112
4113 %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
4114 % replace all variables in types by "any"
4115
4116 ground_type_to_any(T,Exceptions) :- var(T),!,
4117 ( exact_member(T,Exceptions) -> ! % any variable exact member in list is not grounded
4118 ; T=any).
4119 ground_type_to_any(record(Fields),Exceptions) :- !,
4120 % treat records separately, we do not want the list of fields to be bound to any; see B/Tickets/RecordPartiallyTyped
4121 ground_field_types(Fields,Exceptions).
4122 ground_type_to_any(seq(T),Exceptions) :- !, ground_type_to_any(T,Exceptions).
4123 ground_type_to_any(set(T),Exceptions) :- !, ground_type_to_any(T,Exceptions).
4124 ground_type_to_any(couple(A,B),Exceptions) :- !, ground_type_to_any(A,Exceptions), ground_type_to_any(B,Exceptions).
4125 ground_type_to_any(global(_),_) :- !.
4126 ground_type_to_any(freetype(_),_) :- !.
4127 ground_type_to_any(T,_) :- ground(T),!.
4128 ground_type_to_any(T,Exceptions) :-
4129 functor(T,_,Arity),
4130 ground_type_args(Arity,T,Exceptions).
4131 ground_type_args(0,_T,_Exceptions) :- !.
4132 ground_type_args(N,T,Exceptions) :-
4133 arg(N,T,Arg),
4134 ground_type_to_any(Arg,Exceptions),
4135 N2 is N-1,
4136 ground_type_args(N2,T,Exceptions).
4137
4138 ground_field_types(T,Exceptions) :- var(T),!,
4139 ( exact_member(T,Exceptions) -> ! % any variable exact member in list is not grounded
4140 ; print(grounding_open_ended_record),nl, % should we generate a warning here ?
4141 T=[]
4142 ).
4143 ground_field_types([],_) :- !.
4144 ground_field_types([field(Name,Type)|T],Exceptions) :- !,
4145 (var(Name)
4146 -> add_internal_error('Unbound record field name: ',ground_field_types([field(Name,Type)|T],Exceptions))
4147 ; true),
4148 ground_type_to_any(Type,Exceptions),
4149 ground_field_types(T,Exceptions).
4150 ground_field_types(Other,Exceptions) :-
4151 add_internal_error('Illegal record field list: ',ground_field_types(Other,Exceptions)).
4152
4153 % annote variables of becomes_such with before_substitution infos
4154 annotate_becomes_such_vars(Ids1,Pred,Ids2) :-
4155 find_used_primed_ids(Pred,Ids1,BeforeAfter),
4156 maplist(add_before_after_info(BeforeAfter),Ids1,Ids2).
4157 % put optional before/after usage into the information of the identifiers
4158 % makes only sense in the context of becomes_such substitutions
4159 add_before_after_info(BeforeAfter,TId,TId2) :-
4160 def_get_texpr_id(TId,Id),
4161 ? ( member(ba(Id,BeforeId),BeforeAfter) ->
4162 get_texpr_type(TId,Type), get_texpr_info(TId,Info),
4163 create_texpr(identifier(Id),Type,[before_substitution(Id,BeforeId)|Info],TId2)
4164 ; TId = TId2 ).
4165
4166 % find all used pairs of before/after variables, e.g. ba(x,'x$0')
4167 % see becomes_such substitutions
4168 find_used_primed_ids(TExpr,PossibleIds,Uses) :-
4169 prime_identifiers0(PossibleIds,TP0),
4170 get_sorted_ids(TP0,SP0), % sorted list of primed ids
4171 find_used_primed_ids2(SP0,TExpr,[],Uses).
4172 find_used_primed_ids2(SP0,TExpr,In,Out) :-
4173 syntaxtraversion(TExpr,Expr,_,_Infos,Subs,_),
4174 ( (Expr = identifier(FullId),
4175 %member(before_substitution(Id,FullId),Infos) % this info is not available in Event-B mode
4176 ord_member(FullId,SP0),
4177 prime_atom0(Id,FullId))
4178 -> ord_add_element(In,ba(Id,FullId),Uses)
4179 ; In = Uses ),
4180 foldl(find_used_primed_ids2(SP0),Subs,Uses,Out).
4181
4182 %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
4183 % find expressions which are possibly not well-defined
4184 is_possibly_undefined(Expr) :- always_wd(Expr),!,fail.
4185 is_possibly_undefined(Expr) :-
4186 safe_syntaxelement_det(Expr,Subs,_Names,_,_),
4187 % note: can be very long list Subs for set_extension
4188 ? member(Sub,Subs),
4189 get_texpr_info(Sub,Info),
4190 memberchk(contains_wd_condition,Info),!.
4191 is_possibly_undefined(Expr) :- % TODO: detect freetype constructors as not having a WD condition
4192 ? has_top_level_wd_condition(Expr). %%,print(wd(F,Expr)),nl.
4193
4194 has_top_level_wd_condition(Expr) :- functor(Expr,F,_),
4195 ? has_wd_condition(F,Expr).
4196
4197 % a few common cases which are always defined:
4198 always_wd(bool_set).
4199 always_wd(boolean_false).
4200 always_wd(boolean_true).
4201 always_wd(empty_set).
4202 always_wd(identifier(_)).
4203 always_wd(integer(_)).
4204 always_wd(integer_set(_)).
4205 always_wd(real_set).
4206 always_wd(real(_)).
4207 always_wd(string(_)).
4208 always_wd(string_set).
4209 %always_wd(value(_)). ?
4210 always_wd(truth).
4211
4212
4213 always_defined_full_check_or_disprover_mode(_) :- preferences:get_preference(disprover_mode,true),!.
4214 always_defined_full_check_or_disprover_mode(BExpr) :- \+ full_check_is_possibly_undefined(BExpr).
4215
4216 % a version which does the full traversal; can be used before contains_wd_condition has been computed
4217 full_check_is_possibly_undefined(BExpr) :- get_texpr_expr(BExpr,Expr),
4218 full_check_is_possibly_undefined_aux(Expr).
4219 full_check_is_possibly_undefined_aux(Expr) :-
4220 functor(Expr,F,_),has_wd_condition(F,Expr),!.
4221 full_check_is_possibly_undefined_aux(Expr) :-
4222 syntaxtraversion(_,Expr,_,_,Subs,_),
4223 ? member(Sub,Subs),
4224 full_check_is_possibly_undefined(Sub),!.
4225
4226 :- use_module(external_functions,[external_fun_has_wd_condition/1]).
4227 % determine if an operator has an attached WD condition (used to compute contains_wd_condition)
4228 % division and module must not divide by zero
4229 has_wd_condition(div,Expr) :- arg(2,Expr,DIV),
4230 ? \+ definitely_not_zero(DIV).
4231 has_wd_condition(floored_div,Expr) :- arg(2,Expr,DIV),
4232 ? \+ definitely_not_zero(DIV).
4233 has_wd_condition(div_real,Expr) :- arg(2,Expr,DIV),
4234 \+ definitely_not_zero(DIV).
4235 % functions must not be applied to values outside their domain
4236 has_wd_condition(function,_Expr). % if lambda over total domain we could remove wd_condition, but ast_cleanup rule then already replaces it with assertion_expression, which gets optimised away in this case
4237 has_wd_condition(assertion_expression,_). % gets translated from function application
4238 has_wd_condition(modulo,Expr) :- arg(2,Expr,DIV),
4239 ? (\+ definitely_not_zero(DIV) ;
4240 \+ definitely_not_negative(DIV) ;
4241 arg(1,Expr,A1), \+ definitely_not_negative(A1)).
4242 % power_of must have a non-negative exponent (?)
4243 has_wd_condition(power_of,Expr) :- arg(2,Expr,EXP),
4244 \+ definitely_not_negative(EXP).
4245 has_wd_condition(power_of_real,Expr) :- arg(1,Expr,Base), arg(2,Expr,EXP),
4246 (definitely_not_negative(Base)
4247 -> (definitely_not_zero(Base) -> fail % no WD if base > 0
4248 ; definitely_not_negative(EXP) -> fail % 0.0 ^ EXP is defined if EXP >=0
4249 ; true % 0.0 ^ -1.0 is a division by zero
4250 )
4251 ; true). % things like -1.0 ^ 0.5 is not a real number; we could check if EXP is guaranteed an integ
4252 % Note: REAL ** INTEGER has no WD condition, but power_of_real has a WD condition
4253 has_wd_condition(iteration,Expr) :- arg(2,Expr,Idx),
4254 \+ definitely_not_negative(Idx).
4255 % min and max need a non-empty set
4256 % also Atelier-B manual requires the set to have an upper limit
4257 has_wd_condition(max,Expr) :- arg(1,Expr,S), \+ definitely_not_empty_and_finite(S).
4258 has_wd_condition(min,Expr) :- arg(1,Expr,S), \+ definitely_not_empty_and_finite(S).
4259 has_wd_condition(max_real,Expr) :- arg(1,Expr,S), \+ definitely_not_empty_and_finite(S).
4260 has_wd_condition(min_real,Expr) :- arg(1,Expr,S), \+ definitely_not_empty_and_finite(S).
4261 % all the sequence operations must not be applied to non-sequence
4262 % relations and some must not be applied to empty-sequences
4263 has_wd_condition(size,E) :- arg(1,E,S), \+ definitely_sequence(S).
4264 has_wd_condition(first,E) :- arg(1,E,S), \+ definitely_not_empty_sequence(S).
4265 has_wd_condition(last,E) :- arg(1,E,S), \+ definitely_not_empty_sequence(S).
4266 has_wd_condition(front,E) :- arg(1,E,S), \+ definitely_not_empty_sequence(S).
4267 has_wd_condition(tail,E) :- arg(1,E,S), \+ definitely_not_empty_sequence(S).
4268 has_wd_condition(rev,E) :- arg(1,E,S), \+ definitely_sequence(S).
4269 has_wd_condition(concat,_).
4270 has_wd_condition(insert_front,_).
4271 has_wd_condition(insert_tail,_).
4272 has_wd_condition(restrict_front,_).
4273 has_wd_condition(restrict_tail,_).
4274 has_wd_condition(general_concat,_).
4275 % the general intersection must not be applied to an empty set of sets
4276 has_wd_condition(general_intersection,Expr) :- arg(1,Expr,S),
4277 \+ definitely_not_empty_set(S).
4278 has_wd_condition(quantified_intersection,_). % gets translated to general_intersection
4279 % card must not be applied to infinite sets:
4280 has_wd_condition(card,Expr) :- arg(1,Expr,S), \+ definitely_finite(S).
4281 has_wd_condition(general_sum,_). % TO DO: \+ definitely_finite2(comprehension_set(Ids,P))
4282 has_wd_condition(general_product,_). % ditto; note: sets which are summed/multiplied must be finite
4283 has_wd_condition(mu,_). % Z MU Operator
4284 has_wd_condition(freetype_destructor,_).
4285 has_wd_condition(external_function_call,Expr) :- arg(1,Expr,FunName),
4286 external_fun_has_wd_condition(FunName).
4287 has_wd_condition(external_pred_call,Expr) :- arg(1,Expr,FunName),
4288 external_fun_has_wd_condition(FunName).
4289 % external_subst_call?
4290 has_wd_condition(operation_call_in_expr,_). % we now assume all operation calls may have PRE-conditions
4291 % or involve recursion, and thus may loop; TO DO: compute this information per operation by a fixpoint algorithm
4292
4293 definitely_not_zero(b(integer(X),integer,_)) :- integer(X), X \= 0.
4294 definitely_not_zero(b(real(X),real,_)) :- atom(X), construct_real(X,R), R \= 0.0.
4295 definitely_not_negative(b(integer(X),integer,_)) :- number(X), X >= 0.
4296 % to do add more ?: card(_), ...
4297
4298
4299 % see definitely_not_empty_set/1 in bsyntaxtree
4300 definitely_not_empty_and_finite(b(S,_,_)) :- def_not_empty_fin2(S).
4301 def_not_empty_fin2(bool_set).
4302 def_not_empty_fin2(set_extension([_|_])).
4303 def_not_empty_fin2(sequence_extension([_|_])).
4304 def_not_empty_fin2(cartesian_product(A,B)) :- definitely_not_empty_and_finite(A), definitely_not_empty_and_finite(B).
4305 def_not_empty_fin2(union(A,B)) :- definitely_not_empty_and_finite(A), definitely_not_empty_and_finite(B).
4306 def_not_empty_fin2(overwrite(A,B)) :- definitely_not_empty_and_finite(A),definitely_not_empty_and_finite(B).
4307 def_not_empty_fin2(interval(A,B)) :- definitely_not_empty_set(b(interval(A,B),set(integer),[])).
4308 def_not_empty_fin2(value(S)) :- % what about closures ?
4309 definitely_not_empty_finite_value(S). %kernel_objects:not_empty_set(S).
4310
4311
4312 definitely_not_empty_sequence(b(S,_,_)) :- definitely_not_empty_sequence2(S).
4313 definitely_not_empty_sequence2(sequence_extension(_)).
4314
4315 definitely_sequence(b(S,_,_)) :- definitely_sequence2(S).
4316 definitely_sequence2(empty_sequence).
4317 definitely_sequence2(sequence_extension(_)).
4318
4319 :- use_module(typing_tools,[is_provably_finite_type/1, is_infinite_type/1]).
4320 is_infinite_ground_type(Type) :-
4321 ground(Type), is_infinite_type(Type). % non-ground types happen e.g. in test 472
4322
4323 definitely_finite(b(S,Type,_)) :-
4324 (ground(Type)
4325 -> (is_provably_finite_type(Type)
4326 -> true
4327 ; definitely_finite2(S) -> true
4328 %; \+ is_infinite_type(Type) -> print(no_longer_assuming_finite(Type)),nl,nl,fail
4329 )
4330 ; definitely_finite2(S)).
4331 definitely_finite2(bool_set).
4332 definitely_finite2(empty_set).
4333 definitely_finite2(empty_sequence).
4334 definitely_finite2(set_extension(_)).
4335 definitely_finite2(sequence_extension(_)).
4336 definitely_finite2(cartesian_product(A,B)) :- definitely_finite(A), definitely_finite(B).
4337 definitely_finite2(overwrite(A,B)) :- definitely_finite(A), definitely_finite(B).
4338 definitely_finite2(union(A,B)) :- definitely_finite(A), definitely_finite(B).
4339 definitely_finite2(intersection(A,B)) :- (definitely_finite(A) -> true ; definitely_finite(B)).
4340 definitely_finite2(set_subtraction(A,_)) :- definitely_finite(A).
4341 definitely_finite2(domain_restriction(_,B)) :- definitely_finite(B). % A finite does not guarantee finite relation
4342 definitely_finite2(domain_subtraction(_,B)) :- definitely_finite(B).
4343 definitely_finite2(range_restriction(A,_)) :- definitely_finite(A). % B finite does not guarantee finite relation
4344 definitely_finite2(range_subtraction(A,_)) :- definitely_finite(A).
4345 definitely_finite2(interval(_,_)).
4346 definitely_finite2(value(S)) :- nonvar(S),(S=[] ; S=avl_set(_)).
4347 % TO DO: add other operators : comprehension_set(Ids,P)
4348
4349
4350 ?definitely_infinite(b(S,_,_)) :- !,definitely_infinite2(S).
4351 definitely_infinite(S) :- add_internal_error('AST not wrapped:',definitely_infinite(S)),fail.
4352 definitely_infinite2(string_set).
4353 definitely_infinite2(real_set).
4354 definitely_infinite2(integer_set(X)) :-
4355 X='NATURAL' ; X='NATURAL1' ; X='INTEGER'.
4356 definitely_infinite2(seq1(S)) :- definitely_not_empty_set(S).
4357 definitely_infinite2(seq(S)) :- definitely_not_empty_set(S).
4358 definitely_infinite2(cartesian_product(A,B)) :- is_infinite_cart_prod(A,B).
4359 ?definitely_infinite2(pow_subset(S)) :- definitely_infinite(S).
4360 definitely_infinite2(pow1_subset(S)) :- definitely_infinite(S).
4361 definitely_infinite2(fin_subset(S)) :- definitely_infinite(S). % the set of finite subsets is infinite
4362 definitely_infinite2(fin1_subset(S)) :- definitely_infinite(S).
4363 definitely_infinite2(iseq(S)) :- definitely_infinite(S).
4364 definitely_infinite2(iseq1(S)) :- definitely_infinite(S).
4365 definitely_infinite2(perm(S)) :- definitely_infinite(S).
4366 ?definitely_infinite2(value(V)) :- infinite_value_set(V).
4367 definitely_infinite2(relations(A,B)) :- is_infinite_cart_prod(A,B).
4368 definitely_infinite2(partial_function(A,B)) :- is_infinite_cart_prod(A,B).
4369 definitely_infinite2(total_function(A,B)) :-
4370 (definitely_infinite(A) -> definitely_not_empty_set_card_gt1(B) % INTEGER-->{1} is finite, INTEGER-->BOOL is inf.
4371 ? ; definitely_infinite(B) -> definitely_not_empty_set(A)). % {TRUE} --> INTEGER is infinite
4372 definitely_infinite2(total_relation(A,B)) :- definitely_infinite2(total_function(A,B)).
4373 % TODO: partial_injection, total_injection, partial_surjection, total_surjection, total_bijection, partial_bijection,
4374 % surjection_relation, total_surjection_relation
4375 % cf total_surjection_card
4376
4377 % non empty sets with at least two elements:
4378 definitely_not_empty_set_card_gt1(bool_set).
4379 definitely_not_empty_set_card_gt1(A) :- definitely_infinite(A).
4380
4381 is_infinite_cart_prod(A,B) :-
4382 ? (definitely_infinite(A) -> definitely_not_empty_set(B) % INTEGER*{} is finite
4383 ? ; definitely_infinite(B) -> definitely_not_empty_set(A)).
4384
4385 infinite_value_set(V) :- var(V),!,fail.
4386 infinite_value_set(global_set(X)) :-
4387 X='NATURAL' ; X='NATURAL1' ; X='INTEGER'.
4388 infinite_value_set(closure(P,T,B)) :-
4389 % T \= [integer], % otherwise we could intersect with NATURAL,... ????
4390 custom_explicit_sets:is_infinite_closure(P,T,B).
4391 infinite_value_set(freetype(ID)) :- kernel_freetypes:is_infinite_freetype(ID).
4392
4393
4394
4395
4396 % check if %(Ids).(Pred|_) is infinite
4397 infinite_or_symbolic_domain_for_lambda(Ids,b(Expr,pred,_),Kind) :-
4398 ? inf_dom_aux(Expr,Ids,Kind).
4399 inf_dom_aux(member(TID2,InfSet),[TID],infinite) :- same_id(TID,TID2,_),
4400 ? definitely_infinite(InfSet).
4401 inf_dom_aux(truth,Ids,infinite) :-
4402 ? member(TID,Ids), get_texpr_type(TID,Type),
4403 is_infinite_ground_type(Type).
4404 inf_dom_aux(COMP,[TID|_],infinite) :- % A \= "" or A \= 0 or A \= B+1 or A < B*B or ...
4405 ? binary_inf_comparison(COMP,A,B),
4406 get_texpr_type(TID,Type), is_infinite_ground_type(Type),
4407 same_id(A,TID,ID),
4408 not_occurs_in_expr(ID,B). % ensure B does not depend on A; e.g. we have %x.(x/=x | E) is empty
4409 inf_dom_aux(equal(EXTFUN,BOOL),Ids,symbolic) :-
4410 % something like f = %s.(s:STRING & REGEX_MATCH(s,"[a-z]+")=TRUE | s)
4411 get_texpr_expr(EXTFUN,external_function_call(FUN,Args)),
4412 get_texpr_boolean(BOOL,_),
4413 is_symbolic_ext_pred(FUN,Args,Ids).
4414 inf_dom_aux(external_pred_call(FUN,Args),Ids,symbolic) :-
4415 is_symbolic_ext_pred(FUN,Args,Ids).
4416
4417 % a comparator which allows infinitely many values for first argument with fixed second argument
4418 ?binary_inf_comparison(not_equal(A,B),AA,BB) :- sym_unify(A,B,AA,BB).
4419 ?binary_inf_comparison(less(A,B),AA,BB) :- sym_unify(A,B,AA,BB).
4420 ?binary_inf_comparison(less_equal(A,B),AA,BB) :- sym_unify(A,B,AA,BB).
4421 ?binary_inf_comparison(greater(A,B),AA,BB) :- sym_unify(A,B,AA,BB).
4422 ?binary_inf_comparison(greater_equal(A,B),AA,BB) :- sym_unify(A,B,AA,BB).
4423
4424 sym_unify(A,B,A,B).
4425 sym_unify(A,B,B,A).
4426
4427 % not guaranteed to be infinite, but makes sense to keep symbolic
4428 is_symbolic_ext_pred(FUN,Args,[TID|_]) :-
4429 symbolic_ext_pred(FUN),
4430 def_get_texpr_id(TID,ID),
4431 ? (member(A,Args), occurs_in_expr(ID,A) -> true). % ensure the condition is not static and depends on an argument
4432
4433 % external predicates which indicate that the corresponding function should be kept symbolic
4434 symbolic_ext_pred('IS_REGEX').
4435 symbolic_ext_pred('GET_IS_REGEX').
4436 symbolic_ext_pred('REGEX_MATCH').
4437 symbolic_ext_pred('REGEX_IMATCH').
4438 symbolic_ext_pred('GET_IS_REGEX_MATCH').
4439 symbolic_ext_pred('GET_IS_REGEX_IMATCH').
4440 symbolic_ext_pred('STRING_EQUAL_CASE_INSENSITIVE').
4441 symbolic_ext_pred('STRING_IS_ALPHANUMERIC').
4442 symbolic_ext_pred('STRING_IS_DECIMAL').
4443 symbolic_ext_pred('STRING_IS_NUMBER').
4444 symbolic_ext_pred('GET_STRING_EQUAL_CASE_INSENSITIVE').
4445 symbolic_ext_pred('GET_STRING_IS_ALPHANUMERIC').
4446 symbolic_ext_pred('GET_STRING_IS_DECIMAL').
4447 symbolic_ext_pred('GET_STRING_IS_NUMBER').
4448 symbolic_ext_pred('GET_STRING_IS_INT').
4449 symbolic_ext_pred('FILE_EXISTS').
4450 symbolic_ext_pred('GET_FILE_EXISTS').
4451 symbolic_ext_pred('DIRECTORY_EXISTS').
4452 symbolic_ext_pred('GET_DIRECTORY_EXISTS').
4453 % TODO: add more external predicates
4454 %symbolic_ext_pred(X) :- nl,print(not_symbolic(X)),nl,fail.
4455
4456
4457 :- use_module(custom_explicit_sets,[quick_is_definitely_maximal_set/1]).
4458 % should we use is_just_type/1 instead ?? TO DO: check
4459 definitely_maximal_set(b(S,_,_)) :- definitely_maximal2(S).
4460 definitely_maximal2(integer_set('INTEGER')).
4461 definitely_maximal2(bool_set).
4462 definitely_maximal2(string_set).
4463 definitely_maximal2(typeset).
4464 definitely_maximal2(comprehension_set(_,b(truth,_,_))). % also covers is_integer_set(X,'INTEGER')
4465 definitely_maximal2(value(S)) :- nonvar(S),quick_is_definitely_maximal_set(S).
4466 % TO DO: cartesian product, records, ... if useful
4467
4468
4469 % just a sequence consisting of a single element
4470 is_singleton_sequence(b(sequence_extension([ELEMENT]),_,_),ELEMENT).
4471
4472 % check if type does not contain sets
4473 type_contains_no_sets(X) :- var(X),!,fail. % in test 472 we have a variable type
4474 type_contains_no_sets(integer).
4475 type_contains_no_sets(boolean).
4476 type_contains_no_sets(string).
4477 type_contains_no_sets(global(_)).
4478 type_contains_no_sets(couple(A,B)) :- type_contains_no_sets(A), type_contains_no_sets(B).
4479 type_contains_no_sets(record(Fields)) :- field_types_ok(Fields).
4480 field_types_ok([]).
4481 field_types_ok([field(_,Type)|T]) :- type_contains_no_sets(Type), field_types_ok(T).
4482
4483 % ----------------------------------
4484
4485
4486 select_conjunct(Predicate,Conjunction,Prefix,Suffix) :-
4487 conjunction_to_list(Conjunction,List),
4488 append(Prefix,[Predicate|Suffix],List).
4489
4490
4491 data_validation_mode :-
4492 (get_preference(data_validation_mode,true) -> true
4493 ; environ(prob_data_validation_mode,true)).
4494
4495 % optionally provide hints about rewritings or potential improvements
4496 add_hint_message(_,_Msg,_Term,_Span) :- debug_mode(off),
4497 get_preference(performance_monitoring_on,false), % should we use another preference?
4498 !.
4499 add_hint_message(Src,Msg,Term,Span) :-
4500 add_message(Src,Msg,Term,Span).
4501
4502 % ------------------------
4503
4504 % mini partial evaluation / constant expression evaluation of B expressions
4505 % TO DO: unify with b_compile and b_expression_sharing !
4506 % But this one only pre-computes top-level operators; assumes bottom-up traversal
4507
4508 :- use_module(kernel_card_arithmetic,[safe_pown/3]).
4509 :- use_module(library(avl),[avl_size/2]).
4510 pre_compute_static_int_expression(add(A,B),Result) :- % plus
4511 get_integer(A,IA), get_integer(B,IB),
4512 Result is IA+IB.
4513 pre_compute_static_int_expression(minus(A,B),Result) :- % plus
4514 get_integer(A,IA), get_integer(B,IB),
4515 Result is IA-IB.
4516 pre_compute_static_int_expression(unary_minus(A),Result) :- % plus
4517 get_integer(A,IA),
4518 Result is -IA.
4519 pre_compute_static_int_expression(multiplication(A,B),Result) :-
4520 get_integer(A,IA), get_integer(B,IB),
4521 Result is IA*IB.
4522 pre_compute_static_int_expression(div(A,B),Result) :- % TO DO: also add floored_div
4523 get_integer(B,IB), IB \= 0,
4524 get_integer(A,IA),
4525 Result is IA//IB.
4526 pre_compute_static_int_expression(modulo(A,B),Result) :-
4527 get_integer(B,IB), IB > 0,
4528 get_integer(A,IA), IA >= 0,
4529 Result is IA mod IB.
4530 pre_compute_static_int_expression(power_of(A,B),Result) :-
4531 get_integer(A,IA), get_integer(B,IB), IB >= 0,
4532 safe_pown(IA,IB,Result), number(Result).
4533 pre_compute_static_int_expression(card(A),Result) :-
4534 get_nonvar_val(A,AVal),
4535 (AVal=[] -> Result=0
4536 ; AVal=avl_set(AVL) -> avl_size(AVL,Result)).
4537
4538 get_nonvar_val(b(value(V),_,_),V) :- nonvar(V).
4539
4540 % ----------------------------------------
4541