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