1 % (c) 2009-2026 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(bsyntaxtree,
6 [is_texpr/1, % checks if the given argument is a typed expression
7
8 get_texpr_expr/2, % get the expression part of a typed expression
9 get_texpr_type/2, % get the type of a typed expression
10 get_texpr_info/2, % get the list of information of a typed expression
11 get_texpr_id/2, % get the id of a typed identifier, fails if it's not an identifier
12 def_get_texpr_id/2, % same as above, but raises error if arg1 is not an identifier
13 def_get_texpr_ids/2, % maplist of the above, i.e., translate a typed id list into a plain list of id names
14 create_typed_id/3, % create a typed identifier
15 create_typed_ids/3, % create a list of typed identifiers from list of names and types
16 same_id/3, % true if two typed identifiers have the same id
17 same_ids/2, % true if two lists of typed identifiers have the same ids
18 same_ids_and_types/2, % also check types
19 split_names_and_types/3, % split list of typed ids into ids and types
20 get_texpr_exprs/2, % list variant of the above
21 get_texpr_types/2, % list variant of the above
22 get_texpr_infos/2, % list variant of the above
23 get_texpr_ids/2, % list variant of the above
24 get_texpr_pos/2, % get the position of a typed expression
25 get_texpr_pos_infos/2, % the a list containing the position infos, sublist of get_texpr_infos
26 extract_pos_infos/2, % get the position info sub list of an info list
27 copy_pos_infos/3, % copy position infos from one typed expression to another
28 delete_pos_info/2, % delete position info from an info list
29 propagate_pos_info_if_useful/3, % propagate position info from second list if useful
30 merge_info/3, % merge two information lists as well as possible
31 update_infos/3, % provide updates to an existing info list
32 get_info_pos/2, % get the position directly from info field
33 contains_info_pos/1, % true if info field contains position infos
34
35 same_texpr/2, % check if two typed expressions are equal modulo Info fields
36 different_texpr_values/2, % check if two type expressions are WD and definitely denote different values
37
38 create_texpr/4, % creates a typed expression by giving expression, type and infos
39 add_texpr_infos/3, % adds some more information to a typed expression at front
40 add_texpr_info_if_new/3, % adds one info field to typed B expression info list at front if it is new
41 add_texpr_infos_if_new/3, % ditto but list of infos can be added
42 add_info_if_new/3, % adds to info list
43 add_infos_if_new/3, % same for list of info items
44 safe_create_texpr/3, % a version of create_texpr which extracts wd-info from sub-expressionssafe_create_texpr
45 safe_create_texpr/4,
46 texpr_contains_wd_condition/1,
47 sub_expression_contains_wd_condition/1, % utility to check if sub-expression contains wd condition
48
49 get_rodin_name/2, get_precise_rodin_name/2,
50 get_rodin_model_name/2,
51 is_rodin_label_info/1,
52 get_texpr_label/2, get_texpr_labels/2,
53 get_info_labels/2, select_info_labels/3,
54 add_labels_to_texpr/3,
55 get_texpr_description/2, % get @desc pragma for typed expression
56 add_texpr_description/3, % add an additional description by hand
57 info_has_ignore_pragma/1, % check if an info list has an ignore pragma
58 predicate_has_ignore_pragma/1, % ditto for the info list of a predicate
59 always_well_defined/1, always_well_defined_or_disprover_mode/1,
60 always_well_defined_or_wd_reorderings_allowed/1,
61 always_well_defined_or_wd_improvements_allowed/1,
62 finite_wd_set_value/1, finite_set_or_disprover_mode/1,
63 is_truth/1, is_falsity/1,
64 conjunct_predicates/2,
65 conjunct_predicates_with_pos_info/3, conjunct_predicates_with_pos_info/2,
66 is_a_conjunct/3, is_a_conjunct_without_label/3, decompose_conjunct/3,
67 is_a_disjunct/3, is_an_implication/3, is_an_equivalence/3, is_a_negation/2,
68 conjunction_to_list/2,
69 conjunction_to_list_with_rodin_labels/2, % a variation which propagates labels down to conjuncts
70 member_in_conjunction/2, select_member_in_conjunction/3,
71 flatten_conjunctions/2,
72 size_of_conjunction/2,
73 member_in_conjunction_cse/3,
74 disjunct_predicates/2,
75 disjunct_predicates_with_pos_info/3,
76 disjunction_to_list/2,
77 is_a_disjunct_or_implication/4,
78 is_a_conjunct_or_neg_disj/3,
79
80 predicate_components/2, % split a predicate into components which use distinct identifiers
81 predicate_components_in_scope/3, % ditto with an optional list of local variables
82 predicate_components_with_restriction/4,
83 predicate_identifiers/2, predicate_identifiers_in_scope/3,
84
85 project_predicate_on_identifiers/5,
86
87 find_identifier_uses_top_level/2, % not including global sets and constants
88 find_identifier_uses/3, find_identifier_uses_if_necessary/3,
89 find_identifier_uses_l/3,
90 find_typed_identifier_uses/3,
91 find_typed_identifier_uses/2, % not including global sets and constants
92 find_typed_identifier_uses_l/3,
93 find_identifier_uses_for_quantifier_body/3,
94 get_global_identifiers/1, get_global_identifiers/2,
95 occurs_in_expr/2, some_id_occurs_in_expr/2,
96 single_usage_identifier/3,
97 update_used_ids/3,
98 check_computed_used_ids/2,
99
100 create_exists/3, create_or_merge_exists/3,
101 create_exists_or_let_predicate/3,
102 create_exists_opt_liftable/3,
103 create_exists_opt/3, create_exists_opt/4, create_exists_opt/5,
104 not_generated_exists_paras/1,
105 create_forall/3,
106 infer_seq_types_for_tids/3,
107 create_negation/2, is_negation_of/2, get_negated_operator_expr/2,
108 create_implication/3,
109 create_equivalence/3,
110 is_equality/3,
111 create_equality/3, split_equality/3, get_texpr_couple/3,
112 create_couple/3, create_couple/2, nested_couple_to_list/2,
113 create_cartesian_product/3,
114 create_comprehension_set/4,
115 is_eventb_comprehension_set/4, is_eventb_comprehension_set/6,
116 singleton_set_extension/2,
117 is_membership/3, is_membership_or_equality/3,
118 get_lambda_equality/4,
119 is_pow_subset/2, is_pow1_subset/2,
120
121 detect_global_predicates/4,
122
123 definitely_not_empty_set/1, definitely_empty_set/1, definitely_not_empty_finite_value/1,
124 get_integer/2,
125 get_interval/3,
126
127 replace_id_by_expr/4,
128 replace_id_by_expr_with_count/5, % also count number of replacements
129 replace_ids_by_exprs/4,
130 remove_used_id_from_info/3, % remove an id from used_id info field if it exists
131 remove_used_ids_from_info/3, % remove list of ids (order of args different !)
132
133 rename_bt/3, % a simplified version of replace_ids_by_exprs, which assumes target of renamings are variables
134 rename_bt_l/3,
135 remove_bt/4,
136 syntaxtransformation/5,
137 syntaxtransformation_det/5, % faster, non-backtracking version
138 syntaxtransformation_for_renaming/5,
139 remove_renamings/3,
140
141 map_over_bexpr/2, map_over_typed_bexpr/2, map_over_typed_bexpr/3,
142 map_over_typed_bexpr_with_names/2,
143 map_over_bexpr_top_down_acc/3, map_over_typed_bexpr_top_down_acc/3,
144 reduce_over_bexpr/4,
145 transform_bexpr/3, % transform a typed B expression bottom-up
146 transform_bexpr_with_scoping/3, % ditto, but we also provide info about local ids
147 transform_bexpr_td_with_scoping/3, % top-down with scoping
148 transform_bexpr_with_bup_accs/5, transform_bexpr_with_acc/5,
149 non_det_transform_bexpr_with_acc/5, % can be used to generate several transformed expressions
150 uses_implementable_integers/1,
151 min_max_integer_value_used/3, min_max_integer_value_used/5,
152 syntaxtraversion/6,
153 safe_syntaxelement/5,
154 safe_syntaxelement_det/5, % a deterministic, non-backtracking version
155 is_subst_syntaxelement/1,
156 is_syntax_constant/1,
157
158 expand_all_lets/2,
159
160 remove_all_infos/2, extract_info/2, extract_info/3, extract_info_wo_used_ids/2,
161 bsyntax_pattern/2,
162
163 remove_all_infos_and_ground/2,
164
165 check_if_typed_predicate/1,
166 check_if_typed_expression/1,
167 check_if_typed_substitution/1,
168
169 strip_and_norm_ast/2,
170 same_norm_texpr/2,
171 get_texpr_functor/3,
172
173 is_set_type/2, get_set_type/2, get_texpr_set_type/2,
174 is_just_type/1, is_just_type/2,
175 get_texpr_boolean/2,
176
177 create_recursive_compset/6,
178 unique_typed_id/3,
179 mark_bexpr_as_symbolic/2,
180
181 identifier_sub_ast/3, exchange_ast_position/5,
182
183 has_declared_identifier/2, add_declaration_for_identifier/3,
184 check_ast/1, check_ast/2,
185 repair_used_ids/3,
186 print_ast/1,
187 rewrite_if_then_else_expr_to_b/2,
188 normalise_bexpr_for_ml/2
189 ]).
190
191 % meta_predicate annotations should appear before loading any code:
192
193 :- meta_predicate map_over_full_bexpr_no_fail(1,?).
194
195 :- meta_predicate map_over_bexpr(1,?).
196 :- meta_predicate map_over_typed_bexpr(1,?).
197 :- meta_predicate map_over_typed_bexpr(2,?,?).
198 :- meta_predicate map_over_bexpr_top_down_acc(3,?,?).
199 :- meta_predicate map_over_typed_bexpr_top_down_acc(3,?,?).
200
201 :- meta_predicate reduce_over_bexpr(3,?,?,?).
202 :- meta_predicate transform_bexpr(2,?,?).
203 :- meta_predicate l_transform_bexpr(?,2,?).
204 :- meta_predicate transform_bexpr_with_scoping(3,?,?).
205 :- meta_predicate transform_bexpr_td_with_scoping(3,?,?).
206 :- meta_predicate transform_bexpr_with_scoping2(3,?,?,?).
207 :- meta_predicate l_transform_bexpr_with_scoping(?,3,?,?).
208 :- meta_predicate transform_bexpr_with_bup_accs(4,?,?,?,?).
209 :- meta_predicate l_transform_bexpr_with_bup_accs(?,4,?,?,?).
210 :- meta_predicate transform_bexpr_with_acc(4,?,?,?,?).
211 :- meta_predicate l_transform_bexpr_with_acc(?,4,?,?,?).
212 :- meta_predicate non_det_transform_bexpr_with_acc(4,?,?,?,?).
213 :- meta_predicate l_nd_transform_bexpr_with_acc(?,4,?,?,?).
214
215 % -----------
216
217
218 :- use_module(tools).
219
220 :- use_module(module_information,[module_info/2]).
221 :- module_info(group,typechecker).
222 :- module_info(description,'This module provides operations on the type-checked AST.').
223
224 :- use_module(library(lists)).
225 :- use_module(library(ordsets)).
226 :- use_module(library(avl)).
227 :- use_module(library(terms)).
228
229 :- use_module(self_check).
230 :- use_module(error_manager).
231 :- use_module(translate,[print_bexpr/1,translate_bexpression/2]).
232 :- use_module(gensym,[gensym/2]).
233 :- use_module(preferences,[get_preference/2,preference/2]).
234 :- use_module(debug,[debug_mode/1,debug_format/3]).
235
236 :- use_module(typing_tools,[is_finite_type_in_context/2,normalize_type/2]).
237 :- use_module(tools_lists,[convlist_max/4]).
238
239 :- set_prolog_flag(double_quotes, codes).
240
241 %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
242 % basic access to enriched syntax tree
243
244 is_texpr(b(_,_,_)).
245
246 get_texpr_expr(b(Name,_,_),R) :- !,R=Name.
247 get_texpr_expr(E,_) :- add_error_fail(get_texpr_expr,'B Expression not properly wrapped: ',E).
248
249 get_texpr_type(b(_,Type,_),R) :- !, R=Type.
250 get_texpr_type(E,_) :- add_error_fail(get_texpr_type,'B Expression not properly wrapped: ',E).
251 get_texpr_info(b(_,_,Info),R) :- !, R=Info.
252 get_texpr_info(E,_) :- add_error_fail(get_texpr_info,'B Expression not properly wrapped: ',E).
253
254 %! get_texpr_id(+Texpr,-Id)
255 get_texpr_id(b(N,_,_),Id) :- !, N=identifier(Id).
256 get_texpr_id(E,_) :- add_error_fail(get_texpr_id,'B Expression not properly wrapped: ',E).
257 /* same as above: but must succeed */
258 def_get_texpr_id(b(identifier(Id),_,_),R) :- !,R=Id.
259 def_get_texpr_id(b(E,_,_),_) :- !,
260 add_error_fail(def_get_texpr_id,'Could not extract identifier from typed expression: ',E).
261 def_get_texpr_id(ID,_) :- add_error_fail(def_get_texpr_id,'Could not extract identifier, not properly wrapped: ',ID).
262
263 % translate a list of ids with the b/3 wrapper into a plain id list; throw error if not an identifier
264 % used to also be called get_texpr_id_names
265 def_get_texpr_ids(L,Ids) :- maplist(def_get_texpr_id,L,Ids).
266
267 create_typed_id(IDName,Type,b(identifier(IDName),Type,[])).
268
269 create_typed_ids([],[],[]).
270 create_typed_ids([ID|TI],[Type|TT],[TID| TRes]) :-
271 create_typed_id(ID,Type,TID),
272 create_typed_ids(TI,TT,TRes).
273
274 same_id(X,Y,ID) :- get_texpr_id(X,ID), get_texpr_id(Y,ID).
275
276 same_ids([],[]).
277 same_ids([X|Xs],[Y|Ys]) :- same_id(X,Y,_), same_ids(Xs,Ys).
278
279 % check if two lists of identifiers have the same name and types
280 same_ids_and_types([],[]).
281 same_ids_and_types([b(identifier(Id),T1,_)|Xs],[b(identifier(Id),T2,_)|Ys]) :- unify_types_strict(T1,T2),
282 same_ids_and_types(Xs,Ys).
283
284 % split a list of typed identifiers into atomic ids and types
285 split_names_and_types([],N,T) :- !, N=[], T=[].
286 split_names_and_types([Identifier|IdRest],[Name|NRest],[Type|TRest]) :- !,
287 def_get_texpr_id(Identifier,Name),
288 get_texpr_type(Identifier,Type),
289 split_names_and_types(IdRest,NRest,TRest).
290 split_names_and_types(TIDS,N,R) :-
291 add_internal_error('Illegal call to:',split_names_and_types(TIDS,N,R)),fail.
292
293
294
295 % check if two wrapped expressions are equal (modulo associated Info, e.g. source loc info)
296 same_texpr(b(E1,Type1,_),b(E2,Type2,_)) :-
297 % should we do a == check first? probably not as it may traverse entire term (see emails with SICStus 28.1.2015)
298 same_texpr4(E1,Type1,E2,Type2).
299
300 same_texpr4(empty_set,Type1,E2,Type2) :- !, is_empty_set_aux(E2), unify_types_strict(Type1,Type2).
301 same_texpr4(empty_sequence,Type1,E2,Type2) :- !, is_empty_set_aux(E2), unify_types_strict(Type1,Type2).
302 same_texpr4(value(V),Type1,E2,Type2) :- V==[], !, is_empty_set_aux(E2), unify_types_strict(Type1,Type2).
303 same_texpr4(E1,Type1,E2,Type2) :-
304 same_functor(E1,E2),
305 unify_types_strict(Type1,Type2), % can be relevant for test 1544, last assertion to detect if_then_else
306 safe_syntaxelement_det(E1,Subs1,_Names1,_List1,Constant),
307 safe_syntaxelement_det(E2,Subs2,_Names2,_List2,Constant2),
308 Constant==Constant2, % in case we have values with variables inside !
309 same_sub_expressions(Subs1,Subs2).
310
311 same_sub_expressions([],[]).
312 same_sub_expressions([H1|T1],[H2|T2]) :- same_texpr(H1,H2), same_sub_expressions(T1,T2).
313
314 % check if two wrapped expressions definitely denote a different value (and are well-defined)
315 % only detects certain cases !
316 different_texpr_values(b(E1,Type1,I1),b(E2,Type2,I2)) :-
317 different_value(E1,E2,CheckWD),
318 unify_types_strict(Type1,Type2),
319 (CheckWD=false -> true
320 ; always_well_defined_or_wd_improvements_allowed(b(E1,Type1,I1)),
321 always_well_defined_or_wd_improvements_allowed(b(E2,Type2,I2))).
322 different_value(boolean_false,boolean_true,false) :- !.
323 different_value(boolean_true,boolean_false,false) :- !.
324 different_value(integer(X),IY,false) :- get_integer_aux(IY,Y),!, X\=Y.
325 different_value(string(X),string(Y),false) :- !, X\=Y.
326 different_value(value(VX),Y,false) :- !, different_val_from(VX,Y).
327 different_value(empty_set,S,check_wd) :- !, non_empty_set(S).
328 different_value(empty_sequence,S,check_wd) :- !, non_empty_set(S).
329 different_value(S,empty_set,check_wd) :- !, non_empty_set(S).
330 different_value(S,empty_sequence,check_wd) :- !, non_empty_set(S).
331 % should we compare two set_extensions ? couples ? records ? reals/floats?
332
333 different_val_from(Var,_) :- var(Var),!,fail.
334 different_val_from(int(X),IY) :- integer(X), get_integer_aux(IY,Y), X\=Y.
335 different_val_from(fd(X,Gs),value(FY)) :- nonvar(X), nonvar(FY), FY=fd(Y,Gs), nonvar(Y), X\=Y.
336 different_val_from(pred_false,boolean_true).
337 different_val_from(pred_false,value(BY)) :- BY==pred_true.
338 different_val_from(pred_true,boolean_false).
339 different_val_from(pred_true,value(BY)) :- BY==pred_false.
340 different_val_from(string(X),string(Y)) :- !, X\=Y.
341 different_val_from(string(X),value(VY)) :- nonvar(VY), VY=string(Y), nonvar(Y), !, X\=Y.
342 different_val_from(avl_set(node(_,_,_,_,_)),empty_set).
343
344 non_empty_set(set_extension([_|_])).
345 non_empty_set(sequence_extension([_|_])).
346
347
348 get_texpr_exprs([],[]).
349 get_texpr_exprs([E|Rest],[N|NRest]) :- get_texpr_expr(E,N),get_texpr_exprs(Rest,NRest).
350 get_texpr_exprs(b(E,_,_),Res) :- add_internal_error('Illegal call:',get_texpr_infos(b(E,_,_),Res)), Res=[E].
351 get_texpr_types([],[]).
352 get_texpr_types([E|Rest],[T|TRest]) :- get_texpr_type(E,T),get_texpr_types(Rest,TRest).
353 get_texpr_types(b(_,T,_),Res) :- add_internal_error('Illegal call:',get_texpr_infos(b(_,T,_),Res)), Res=[T].
354 get_texpr_infos([],[]).
355 get_texpr_infos([E|Rest],[I|IRest]) :- get_texpr_info(E,I),get_texpr_infos(Rest,IRest).
356 get_texpr_infos(b(_,_,I),Res) :- add_internal_error('Illegal call:',get_texpr_infos(b(_,_,I),Res)), Res=[I].
357 get_texpr_ids([],[]).
358 ?get_texpr_ids([E|Rest],[I|IRest]) :- get_texpr_id(E,I),get_texpr_ids(Rest,IRest).
359
360 get_texpr_pos(TExpr,Pos) :-
361 get_texpr_info(TExpr,Infos),
362 ? ( member(nodeid(Pos1),Infos) -> !,Pos=Pos1
363 ; Pos = none).
364
365 get_texpr_pos_infos(b(_,_,Infos),PosInfos) :- extract_pos_infos(Infos,PosInfos).
366
367 % similar to get_texpr_pos, but returns sub-list of infos relating to position
368 extract_pos_infos(Infos,InfoRes) :-
369 ? ( member(nodeid(Pos1),Infos) -> !,InfoRes=[nodeid(Pos1)]
370 ; InfoRes = []).
371
372 % copy position info from first arg to second argument
373 copy_pos_infos(b(_,_,Infos1),Arg2,Res) :-
374 ? member(nodeid(Pos1),Infos1),!,
375 Arg2 = b(E,T,Infos2), Res = b(E,T,Infos3),
376 delete_pos_info(Infos2,Infos2d),
377 Infos3 = [nodeid(Pos1)|Infos2d].
378 copy_pos_infos(_,TE,TE).
379
380 delete_pos_info(Infos1,Infos2) :-
381 ? select(nodeid(_),Infos1,D),!, Infos2=D.
382 %delete(Infos1,nodeid(_),Infos2).
383 delete_pos_info(I,I).
384
385 % propagate position info from second list to first one if it has better position info
386 propagate_pos_info_if_useful(Infos,AuxInfos,NewInfos) :-
387 ? member(nodeid(Pos2),AuxInfos),
388 \+ derived_pos(Pos2),!, % potentially useful position info to propagate
389 ? (select(nodeid(Pos1),Infos,Infos2)
390 -> (derived_pos(Pos1)
391 -> NewInfos = [nodeid(Pos2)|Infos2] % we have better position info now
392 ; NewInfos = Infos % we already have a position info
393 )
394 ; NewInfos = [nodeid(Pos2)|Infos]
395 ).
396 propagate_pos_info_if_useful(Infos,_,Infos).
397
398 % derived position; not precise instrinsic label at top-level
399 derived_pos(rodin_derived_context_pos(_,_,_)).
400
401
402 ?get_info_pos(Infos,Pos) :- (member(nodeid(Pos1),Infos) -> Pos=Pos1 ; Pos=none).
403 contains_info_pos(Infos) :- (member(nodeid(NI),Infos) -> NI \= none).
404
405 create_texpr(Expr,Type,Info,b(Expr,Type,Info)).
406
407 add_texpr_infos(b(Expr,Type,Old),Infos,b(Expr,Type,New)) :- !,
408 append(Infos,Old,New).
409 add_texpr_infos(Other,Infos,Res) :-
410 add_internal_error('Illegal call, not BExpr:',add_texpr_infos(Other,Infos,Res)),fail.
411
412 add_texpr_info_if_new(b(Expr,Type,Old),Info,b(Expr,Type,New)) :- !,
413 add_info_if_new(Old,Info,New).
414 add_texpr_info_if_new(Other,Infos,Res) :-
415 add_internal_error('Illegal call, not BExpr:',add_texpr_info_if_new(Other,Infos,Res)),fail.
416 % add multiple infos:
417 add_texpr_infos_if_new(b(Expr,Type,Old),Infos,b(Expr,Type,New)) :-
418 add_infos_if_new(Infos,Old,New).
419
420 % add to info list:
421 add_info_if_new(Old,Info,New) :-
422 ? (member(Info,Old) -> New=Old ; New = [Info|Old]).
423
424 add_infos_if_new([]) --> [].
425 add_infos_if_new([Info|T]) --> add_info(Info), add_infos_if_new(T).
426 add_info(Info,Old,New) :-
427 ? (member(Info,Old) -> New=Old ; New = [Info|Old]).
428
429
430 % try and extract the Rodin name of a predicate or expression
431 get_rodin_name(Expression,LabelName) :-
432 get_texpr_pos(Expression,Pos),
433 (Pos = rodinpos(LabelName,_) -> LabelName \= []
434 ; Pos = rodinpos(_Model,LabelName,_) -> LabelName \= [] % new rodinpos
435 ; Pos = rodin_derived_context_pos(_Model,_ContextTerm,Label) % ContextTerm can be e.g. event(isqrt,guard)
436 -> atom_concat(Label,' (part)',LabelName) % happens when a guard/predicate is split by ProB
437 ).
438
439 get_precise_rodin_name(Expression,LabelName) :-
440 get_texpr_pos(Expression,Pos),
441 (Pos = rodinpos(LabelName,_) -> LabelName \= []
442 ; Pos = rodinpos(_Model,LabelName,_) -> LabelName \= [] % new rodinpos
443 ).
444
445 get_rodin_model_name(Expression,Model) :-
446 get_texpr_pos(Expression,rodinpos(Model,Name,_)), Name \= []. % new rodinpos
447 % Note: only precise position label, not rodin_derived_context_pos
448
449 % try and extract the Rodin name or label pragma of a predicate or expression
450 get_texpr_labels(TExpr,Label) :-
451 get_texpr_info(TExpr,Infos),
452 ? member(I,Infos), info_label(I,Label).
453 get_info_labels(Infos,LabelList) :-
454 ? member(I,Infos), info_label(I,LabelList).
455 select_info_labels(LabelList,Infos,Rest) :-
456 ? select(I,Infos,Rest), info_label(I,LabelList).
457 info_label(nodeid(NodeID),[Name]) :- nodeid_info_label(NodeID,Name).
458 info_label(label(LabelList),LabelList).
459
460 nodeid_info_label(rodinpos(Name,_),Name) :- Name \= [].
461 nodeid_info_label(rodinpos(Model,Name,_),FullName) :- Name \= [], % new rodinpos
462 ajoin([Model,':',Name], FullName). % TO DO: if only one level; don't do this
463 % TODO: provide separate way to access this derived information:
464 %nodeid_info_label(rodin_derived_context_pos(Model,Context,Label),FullName) :-
465 % ajoin([Model,'.',Context,':',Label], FullName).
466
467
468 add_labels_to_texpr(E,[],R) :- !, R=E. % no labels to add
469 add_labels_to_texpr(b(E,T,I),Labels,b(E,T,NewI)) :-
470 (select(label(OldList),I,Rest)
471 -> append(Labels,OldList,NewList), NewI=[label(NewList)|Rest]
472 % TO DO: what if we have Rodin labels
473 ; NewI = [label(Labels)|I]
474 ).
475
476 ?get_texpr_label(TExpr,Label) :- get_texpr_labels(TExpr,Labels), member(Label,Labels).
477
478 get_texpr_description(TExpr,Description) :-
479 get_texpr_info(TExpr,Infos),
480 memberchk(description(Description),Infos).
481
482 add_texpr_description(b(E,T,I),Description,b(E,T,[description(Description)|I])) :-
483 (atom(Description) -> true ;
484 add_error(add_texpr_description,'Non-atomic description:',Description)).
485
486 % check if an info list has an ignore pragma
487 info_has_ignore_pragma(Infos) :-
488 ? member(description('prob-ignore'),Infos).
489 % detect_prob_ignore ast_cleanup rule also generates this description annotation
490
491 predicate_has_ignore_pragma(b(_E,pred,I)) :-
492 %add_message(check_prob_ignore,'Pred: ',b(_E,pred,I),I),
493 ? info_has_ignore_pragma(I).
494
495 %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
496
497 :- assert_must_succeed( (E = "1/2",
498 bmachine:b_parse_machine_expression_from_codes(E,ET,Type,false,Err),
499 Type==integer, Err==none, always_well_defined(ET) ) ).
500 :- assert_must_succeed( (E = "3 mod 2",
501 bmachine:b_parse_machine_expression_from_codes(E,ET,Type,false,Err),
502 Type==integer, Err==none, always_well_defined(ET) ) ).
503 :- assert_must_succeed( (E = "1/0",
504 bmachine:b_parse_machine_expression_from_codes(E,ET,Type,false,Err),
505 Type==integer, Err==none, \+ always_well_defined(ET) ) ).
506 :- assert_must_succeed( (E = "2*(3 mod card({}))",
507 bmachine:b_parse_machine_expression_from_codes(E,ET,Type,false,Err),
508 Type==integer, Err==none, \+ always_well_defined(ET) ) ).
509 :- assert_must_succeed( (E = "1/(2+1-3)",
510 bmachine:b_parse_machine_expression_from_codes(E,ET,Type,false,Err),
511 Type==integer, Err==none, \+ always_well_defined(ET) ) ).
512 :- assert_must_succeed( (E = "max({1,2,3,0})",
513 bmachine:b_parse_machine_expression_from_codes(E,ET,Type,false,Err),
514 Type==integer, Err==none, always_well_defined(ET) ) ).
515 :- assert_must_succeed( (E = "min({1,2,3,0})",
516 bmachine:b_parse_machine_expression_from_codes(E,ET,Type,false,Err),
517 Type==integer, Err==none, always_well_defined(ET) ) ).
518 :- assert_must_succeed( (E = "min({1,2,3,0}-(0..4))",
519 bmachine:b_parse_machine_expression_from_codes(E,ET,Type,false,Err),
520 Type==integer, Err==none, \+ always_well_defined(ET) ) ).
521 :- assert_must_succeed( (E = "2+max({1,2,3, 1/0})",
522 bmachine:b_parse_machine_expression_from_codes(E,ET,Type,false,Err),
523 Type==integer, Err==none,\+ always_well_defined(ET) ) ).
524 :- assert_must_succeed( (E = "2-card({1,2,3})",
525 bmachine:b_parse_machine_expression_from_codes(E,ET,Type,false,Err),
526 Type==integer, Err==none, always_well_defined(ET) ) ).
527 :- assert_must_succeed( (E = "2-card({1,2,3, 1/0})",
528 bmachine:b_parse_machine_expression_from_codes(E,ET,Type,false,Err),
529 Type==integer, Err==none,\+ always_well_defined(ET) ) ).
530 :- assert_must_succeed( (E = "bool(2-size([1,2,3, 1/0])=3)",
531 bmachine:b_parse_machine_expression_from_codes(E,ET,Type,false,Err),
532 Type==boolean, Err==none, \+ always_well_defined(ET) ) ).
533 :- assert_must_succeed( (E = "bool(2-size([1,2,3, 1/2, 3 mod 2, 3**2])=size([]))",
534 bmachine:b_parse_machine_expression_from_codes(E,ET,Type,false,Err),
535 Type==boolean, Err==none, always_well_defined(ET) ) ).
536
537 always_well_defined_or_wd_reorderings_allowed(BE) :- % allow re-ordering to improve Left-to-right WD
538 (preferences:preference(disprover_mode,true) -> true % we can assume all calls are well-defined
539 ; preferences:preference(allow_improving_wd_mode,true) -> true
540 ; preferences:preference(data_validation_mode,true) -> true
541 ; always_well_defined_or_discharged(BE)).
542 always_well_defined_or_wd_improvements_allowed(BE) :- % allow to remove useless calls which could be non-WD
543 % example #x(x = f(...)) -> btrue or f[{}] --> {}
544 always_well_defined_or_wd_reorderings_allowed(BE). % we currently use the same definition
545 always_well_defined_or_disprover_mode(BE) :-
546 (preferences:preference(disprover_mode,true) -> true % we can assume all calls are well-defined
547 ; always_well_defined_or_discharged(BE)).
548
549 always_well_defined_or_discharged(b(E,_,Infos)) :- !,
550 (nonmember(contains_wd_condition,Infos) -> true
551 ; always_wd(E) -> true % some special rules
552 ? ; member(discharged_wd_po,Infos) -> true
553 %; nl, functor(E,F,N), F \= function, print(non_wd(F,N)),nl,nl,fail
554 ).
555 always_well_defined_or_discharged(E) :-
556 add_error_fail(always_well_defined,'Illegal call: ',always_well_defined_or_discharged(E)).
557
558 % should ensure that there is no failure and no error raised
559 always_well_defined(b(E,_,Infos)) :- !,
560 (nonmember(contains_wd_condition,Infos) -> true
561 ; always_wd(E) -> true % some special rules
562 %; nl, functor(E,F,N), F \= function, print(non_wd(F,N)),nl,nl,fail
563 ).
564 always_well_defined(E) :- add_error_fail(always_well_defined,'Illegal call: ',always_well_defined(E)).
565
566
567 :- assert_must_succeed( always_wd(div( b(integer(2),integer,[]), b(integer(2),integer,[]) )) ).
568 :- assert_must_fail( always_wd(div( b(integer(2),integer,[]), b(integer(0),integer,[]) )) ).
569 :- assert_must_succeed( always_wd(modulo( b(integer(2),integer,[]), b(integer(2),integer,[]) )) ).
570 :- assert_must_fail( always_wd(modulo( b(integer(2),integer,[]), b(integer(0),integer,[]) )) ).
571 :- assert_must_fail( always_wd(modulo( b(integer(2),integer,[]), b(integer(-2),integer,[]) )) ).
572 :- assert_must_fail( always_wd(modulo( b(integer(-1),integer,[]), b(integer(2),integer,[]) )) ).
573 :- assert_must_succeed( always_wd(power_of( b(integer(2),integer,[]), b(integer(3),integer,[]) )) ).
574 :- assert_must_succeed( always_wd(power_of( b(integer(2),integer,[]), b(integer(0),integer,[]) )) ).
575 :- assert_must_fail( always_wd(power_of( b(integer(2),integer,[]), b(integer(-1),integer,[]) )) ).
576
577 % catch cases where the construct is currently so instantiated that we can determine that it is well-defined
578 % can happen e.g. during closure compilation
579 :- use_module(custom_explicit_sets,[check_unique_in_domain_of_avlset/2]).
580 :- use_module(kernel_tools,[ground_value/1]).
581 always_wd(power_of(X,Y)) :- get_integer(Y,Val), Val>=0,
582 (eventb_mode -> get_integer(X,ValX), ValX >=0
583 ; always_well_defined(X)).
584 always_wd(div(X,Y)) :- get_integer(Y,Val), Val\=0, always_well_defined(X).
585 always_wd(modulo(X,Y)) :- get_integer(Y,Val), Val>0, % Z Live allows negative numbers here it seems, cf modulo2
586 (z_or_tla_minor_mode -> true % in Z, TLA we can have negative numbers here
587 ; get_integer(X,ValX), ValX>=0).
588 always_wd(function(X,Y)) :- nonvar(X),
589 X= b(value(AVLSET),_,_), nonvar(AVLSET), AVLSET=avl_set(AVL),
590 always_wd_avl_function(AVL,Y).
591 always_wd(min(X)) :- non_empty_finite_wd_set_value(X).
592 always_wd(max(X)) :- non_empty_finite_wd_set_value(X).
593 always_wd(card(X)) :- finite_wd_set_value(X).
594 always_wd(size(X)) :- finite_wd_seq_value(X).
595 always_wd(first(X)) :- non_empty_wd_seq_value(X).
596 always_wd(front(X)) :- non_empty_wd_seq_value(X).
597 always_wd(last(X)) :- non_empty_wd_seq_value(X).
598 always_wd(tail(X)) :- non_empty_wd_seq_value(X). % TO DO: add restrict_front, restrict_tail ?
599 always_wd(rev(X)) :- finite_wd_seq_value(X).
600 always_wd(concat(X,Y)) :- finite_wd_seq_value(X), finite_wd_seq_value(Y).
601 always_wd(insert_front(_,Y)) :- finite_wd_seq_value(Y).
602 always_wd(insert_tail(X,_)) :- finite_wd_seq_value(X).
603
604 always_wd(general_intersection(X)) :- non_empty_finite_wd_set_value(X).
605 always_wd(value(_)). % we have already computed the value and will raise WD error; to be 100 % safe we could restrict this to ground values
606 % other candidates: size(_), first(_) last(_) tail(_) front(_) restrict_front(_,_) restrict_tail(_,_) rel_iterate(_,_)
607 always_wd(typeset).
608 % operators that are always wd on their own:
609 always_wd(record_field(RecEx,FieldName)) :- ground(FieldName),
610 always_well_defined(RecEx).
611 always_wd(unary_minus(A)) :- always_well_defined(A).
612 always_wd(unary_minus_real(A)) :- always_well_defined(A).
613 always_wd(first_of_pair(A)) :- always_well_defined(A).
614 always_wd(add(A,B)) :- always_well_defined(A),always_well_defined(B).
615 always_wd(add_real(A,B)) :- always_well_defined(A),always_well_defined(B).
616 always_wd(minus(A,B)) :- always_well_defined(A),always_well_defined(B).
617 always_wd(minus_real(A,B)) :- always_well_defined(A),always_well_defined(B).
618 always_wd(multiplication(A,B)) :- always_well_defined(A),always_well_defined(B).
619 always_wd(multiplication_real(A,B)) :- always_well_defined(A),always_well_defined(B).
620 always_wd(equal(A,B)) :- always_well_defined(A),always_well_defined(B).
621 always_wd(not_equal(A,B)) :- always_well_defined(A),always_well_defined(B).
622 always_wd(less_equal(A,B)) :- always_well_defined(A),always_well_defined(B).
623 always_wd(less_equal_real(A,B)) :- always_well_defined(A),always_well_defined(B).
624 always_wd(greater_equal(A,B)) :- always_well_defined(A),always_well_defined(B).
625 always_wd(less(A,B)) :- always_well_defined(A),always_well_defined(B).
626 always_wd(less_real(A,B)) :- always_well_defined(A),always_well_defined(B).
627 always_wd(greater(A,B)) :- always_well_defined(A),always_well_defined(B).
628 always_wd(couple(A,B)) :- always_well_defined(A),always_well_defined(B).
629 % TO DO: add more/all other operators ?
630
631 always_wd_avl_function(AVL,Y) :- nonvar(Y), Y= b(value(Val),_,_),
632 ground_value(Val), !,
633 % Warning: this does not check that the whole AVL is a function; just this particular lookup is ok
634 check_unique_in_domain_of_avlset(Val,AVL). % ,print(ok),nl.
635 always_wd_avl_function(AVL,Y) :- always_well_defined(Y),
636 custom_explicit_sets:quick_definitely_maximal_total_function_avl(AVL).
637
638 % non empty set with WD elements
639 non_empty_finite_wd_set_value(b(E,_,_)) :- non_empty_fin_wd_set2(E).
640 non_empty_fin_wd_set2(bool_set).
641 non_empty_fin_wd_set2(value(X)) :- definitely_not_empty_finite_value(X).
642 non_empty_fin_wd_set2(set_extension(S)) :- l_always_well_defined(S). % the set_extension could contain wd_errors !!
643 non_empty_fin_wd_set2(sequence_extension(S)) :- l_always_well_defined(S). % ditto
644 non_empty_fin_wd_set2(interval(A,B)) :- get_integer(A,IA), get_integer(B,IB), IA =< IB.
645 % see not_empty_set_aux
646 definitely_not_empty_finite_value(X) :- var(X),!,fail.
647 definitely_not_empty_finite_value(avl_set(_)).
648 definitely_not_empty_finite_value([_|_]).
649 definitely_not_empty_finite_value(closure(P,T,B)) :-
650 custom_explicit_sets:is_interval_closure(P,T,B,LOW,UP), integer(LOW),integer(UP), LOW =< UP.
651 % TODO: pow_subset of finite values
652
653 non_empty_wd_seq_value(b(E,_,_)) :- non_empty_seq2(E).
654 non_empty_seq2(value(X)) :- definitely_not_empty_seq(X).
655 non_empty_seq2(sequence_extension(S)) :- l_always_well_defined(S), S=[_|_].
656
657 definitely_not_empty_seq(X) :- var(X),!,fail.
658 definitely_not_empty_seq(avl_set(A)) :- custom_explicit_sets:is_avl_sequence(A).
659 definitely_not_empty_seq([El1|T]) :- T==[],nonvar(El1), El1=(IDX,_), IDX==int(1). % TO DO: add more cases ?
660
661
662 finite_set_or_disprover_mode(Set) :-
663 (preferences:preference(disprover_mode,true) -> true % we can assume all calls are well-defined
664 ; finite_wd_set_value(Set)).
665
666 :- use_module(typing_tools,[is_provably_finite_type/1]).
667 % we could also use is_finite_type_in_context to allow deferred sets to be counted as finite
668 finite_wd_set_value(b(E,T,_)) :- !, (finite_set2(E) -> true ; is_provably_finite_type(T)).
669 finite_wd_set_value(E) :- add_internal_error('Not a BExpr: ',E),fail.
670 finite_set2(empty_set).
671 finite_set2(empty_sequence).
672 finite_set2(value(X)) :- X==[] -> true ; definitely_not_empty_finite_value(X).
673 finite_set2(set_extension(S)) :- l_always_well_defined(S). % the set_extension could contain wd_errors !!
674 finite_set2(sequence_extension(S)) :- l_always_well_defined(S). % ditto
675
676 finite_wd_seq_value(b(E,_,_)) :- finite_seq2(E).
677 finite_seq2(empty_set).
678 finite_seq2(empty_sequence).
679 finite_seq2(value(X)) :- finite_seq_value(X).
680 finite_seq2(sequence_extension(S)) :- l_always_well_defined(S).
681
682 finite_seq_value(X) :- var(X),!,fail.
683 finite_seq_value([]).
684 finite_seq_value(avl_set(A)) :- custom_explicit_sets:is_avl_sequence(A).
685 % it could be expensive to check if non empty list is a B sequence ??
686
687 l_always_well_defined([]).
688 l_always_well_defined([H|T]) :- always_well_defined(H), l_always_well_defined(T).
689
690 ?is_truth(b(F,pred,_)) :- is_truth_aux(F).
691 is_truth_aux(truth).
692 is_truth_aux(value(V)) :- V==pred_true. % can occur in CSE mode
693
694 is_falsity(b(F,pred,_)) :- is_falsity_aux(F).
695 is_falsity_aux(falsity).
696 is_falsity_aux(value(V)) :- V==pred_false. % can occur in CSE mode
697
698 % conjunction of a list of predicates
699 % NOTE: bsyntaxtree:conjunct_predicates([P1,P2,P3],R). --> generates R = b(conjunct(b(conjunct(P1,P2),pred,[]),P3),pred,[])
700 conjunct_predicates(V,R) :- var(V),!, add_internal_error('Variable conjunction list: ',conjunct_predicates(V,R)),fail.
701 conjunct_predicates([],b(truth,pred,[])).
702 conjunct_predicates([P|Rest],Result) :- conjunct2(Rest,P,Result).
703 conjunct2([],P,P).
704 conjunct2([Q|Rest],P,Result) :- conjunct3(P,Q,R), conjunct2(Rest,R,Result).
705 conjunct3(b(truth,_,_),P,P) :- !.
706 conjunct3(P,b(truth,_,_),P) :- !.
707 conjunct3(A,B,b(conjunct(A,B),pred,NewInfo)) :- extract_info(A,B,NewInfo).
708
709 % disjunction of a list of predicates
710 disjunct_predicates([],b(falsity,pred,[])).
711 disjunct_predicates([P|Rest],Result) :- disjunct2(Rest,P,Result).
712 disjunct2([],P,P).
713 disjunct2([Q|Rest],P,Result) :- disjunct3(P,Q,R), disjunct2(Rest,R,Result).
714 disjunct3(b(falsity,_,_),P,R) :- !, R=P.
715 disjunct3(b(truth,T,I),_,R) :- !, R=b(truth,T,I).
716 disjunct3(P,b(falsity,_,_),R) :- !, R=P.
717 disjunct3(_,b(truth,T,I),R) :- !, R=b(truth,T,I).
718 disjunct3(A,B,b(disjunct(A,B),pred,NewInfo)) :- extract_info(A,B,NewInfo).
719
720 % conjunct two predicates and try and construct position information
721 conjunct_predicates_with_pos_info(A,B,AB) :- is_truth(B),!, AB=A.
722 conjunct_predicates_with_pos_info(A,B,AB) :- is_truth(A),!, AB=B.
723 conjunct_predicates_with_pos_info(A,B,AB) :-
724 conjunct_predicates([A,B],AB0), % this may contain position info if B is truth; hence we do check above
725 (try_get_merged_position_info(A,B,ABI)
726 -> add_texpr_infos(AB0,[ABI],AB) %,print(abi(ABI)),nl
727 ; AB=AB0).
728
729 % disjunct two predicates and try and construct position information
730 disjunct_predicates_with_pos_info(A,B,AB) :-
731 disjunct_predicates([A,B],AB0),
732 (try_get_merged_position_info(A,B,ABI)
733 -> add_texpr_infos(AB0,[ABI],AB) %,print(abi(ABI)),nl
734 ; AB=AB0).
735
736 try_get_merged_position_info(b(_,_,I1),b(_,_,I2),PosInfo) :-
737 (try_get_merged_position_info_aux(I1,I2,MergedInfo) -> PosInfo = MergedInfo
738 ? ; get_non_label_posinfo(Pos1,I1) -> PosInfo=nodeid(Pos1)
739 ? ; get_non_label_posinfo(Pos2,I2) -> PosInfo=nodeid(Pos2)
740 ).
741 try_get_merged_position_info_aux(I1,I2,nodeid(pos(C,Filenumber,Srow,Scol,Erow,Ecol))) :-
742 ? member(nodeid(pos(C1,Filenumber,Srow1,Scol1,Erow1,Ecol1)),I1),
743 (number(C1),number(Srow1),number(Scol1),number(Erow1),number(Ecol1)
744 -> true ; add_internal_error('Info field 1 not yet instantiated: ',try_get_merged_position_info(I1)),fail),
745 !,
746 ? member(nodeid(pos(C2,Filenumber,Srow2,Scol2,Erow2,Ecol2)),I2),
747 (number(C2),number(Srow2),number(Scol2),number(Erow2),number(Ecol2)
748 -> true ; add_internal_error('Info field 2 not yet instantiated: ',try_get_merged_position_info(I2)),fail),
749 !,
750 % merge position info if in same file
751 (C1 =< C2 -> C=C1, Srow=Srow1,Scol=Scol1 ; C=C2, Srow=Srow2,Scol=Scol2),
752 ((Erow1 > Erow2 ; Erow1=Erow2, Ecol1 >= Ecol2)
753 -> Erow =Erow1, Ecol=Ecol1
754 ; Erow =Erow2, Ecol=Ecol2).
755
756 % get position info which is not a label; label info should not be propagated to outer conjuncts/disjuncts/...
757 ?get_non_label_posinfo(Pos,Infos) :- member(nodeid(Pos),Infos),
758 \+ functor(Pos,rodinpos,_).
759
760 ?get_texpr_non_label_posinfo(b(_,_,Infos),nodeid(Pos)) :- get_non_label_posinfo(Pos,Infos).
761
762 % conjunct list of predicates and try and construct position information
763 conjunct_predicates_with_pos_info([H|T],Res) :- is_truth(H),!,
764 (T=[] -> Res = H ; conjunct_predicates_with_pos_info(T,Res)).
765 conjunct_predicates_with_pos_info([H|T],Res) :-
766 last_non_truth(T,none,Last), % the truth elements will be removed and are not relevant; get last relevant predicate
767 Last \= none,
768 try_get_merged_position_info(H,Last,MergedPosInfo), % try and merge position of first and last element
769 !,
770 conjunct_predicates([H|T],Res0),
771 add_texpr_infos(Res0,[MergedPosInfo],Res). % Res0 should have no nodeid field
772 conjunct_predicates_with_pos_info(L,Res) :- conjunct_predicates(L,Res).
773
774 :- assert_must_succeed((bsyntaxtree:last_non_truth([a,b,c],none,L),L==c)).
775 :- assert_must_succeed((bsyntaxtree:last_non_truth([a,b,c,b(truth,pred,[])],none,L),L==c)).
776
777 % get last non-truth element and filter out all truth elements
778 last_non_truth([],Acc,Acc).
779 last_non_truth([H|T],NonTruth,Last) :- is_truth(H),!, last_non_truth(T,NonTruth,Last).
780 last_non_truth([H|T],_,Last) :- last_non_truth(T,H,Last).
781
782
783 texpr_contains_wd_condition(b(_,_,Info)) :- !, memberchk(contains_wd_condition,Info).
784 texpr_contains_wd_condition(E) :- add_internal_error('Not a texpr: ',texpr_contains_wd_condition(E)).
785
786 % a version of create_texpr which collects automatically important infos from sub-expressions
787 safe_create_texpr(Expr,Type,b(Expr,Type,Info)) :- %
788 ? (sub_expression_contains_wd_condition(Expr) -> Info = [contains_wd_condition] ; Info=[]).
789
790 safe_create_texpr(Expr,Type,Info,b(Expr,Type,FullInfo)) :- %
791 ? ((sub_expression_contains_wd_condition(Expr), nonmember(contains_wd_condition, Info)) -> FullInfo = [contains_wd_condition|Info] ; FullInfo=Info).
792
793 ?sub_expression_contains_wd_condition(Expr) :- sub_expression_contains_wd_condition(Expr,_).
794 sub_expression_contains_wd_condition(Expr,Sub) :-
795 safe_syntaxelement_det(Expr,Subs,_Names,_L,_C),
796 ? member(b(Sub,_,Infos),Subs),
797 (var(Infos)
798 -> add_internal_error('Typed expression not sufficiently instantiated (variable Infos): ',sub_expression_contains_wd_condition(Expr)),
799 fail
800 ; memberchk(contains_wd_condition,Infos)).
801
802 % provide updated infos (e.g., reads(...)) and remove any old info fields with same functor
803 update_infos([],Infos,Infos).
804 update_infos([Update|T],OldInfos,NewInfos) :-
805 functor(Update,F,N),
806 functor(Old,F,N),
807 delete(OldInfos,Old,OldInfos1),
808 update_infos(T,[Update|OldInfos1],NewInfos).
809
810 % merge two info lists and try to reconcile position information:
811 merge_info(Info1,Info2,Res) :-
812 merge_imp_info2(Info2,Info1,NewInfo),
813 (try_get_merged_position_info_aux(Info1,Info2,NewPos)
814 -> delete_pos_info(NewInfo,NI2),
815 Res = [NewPos|NI2]
816 ; Res = NewInfo).
817
818 % extract important info but without used_ids:
819 extract_info_wo_used_ids(b(_,_,Info1),Info) :-
820 extract_pos_infos(Info1,PosInfos),
821 extract_just_important_info_aux(Info1,[],I1),
822 append(PosInfos,I1,Info).
823 extract_info_wo_used_ids_and_pos(b(_,_,Info1),b(_,_,Info2),Info) :-
824 extract_just_important_info_aux(Info1,[],I1),
825 extract_just_important_info_aux(Info2,I1,Info).
826
827 % extract important info from one sub-expression:
828 extract_info(b(_,_,Info1),NewInfo) :-
829 extract_imp_info1(Info1,I1),!, NewInfo = I1.
830 extract_info(A,R) :-
831 add_internal_error('Could not extract info: ',extract_info(A,R)),
832 R=[].
833 % extract imortant info fields from two (sub-)expressions
834 extract_info(b(_,_,Info1),b(_,_,Info2),NewInfo) :-
835 ? merge_imp_info2(Info1,Info2,II),!, NewInfo = II.
836 %:- use_module(library(ordsets),[ord_intersection/3]).
837 % ord_intersection(Info1,Info2,NewInfo),!.
838 % TO DO: should we merge nodeid position information !?
839 extract_info(A,B,R) :- add_internal_error('Could not extract info: ',extract_info(A,B,R)),
840 R=[].
841
842 % extract important info and used_ids
843 extract_imp_info1([],[]).
844 extract_imp_info1([H|T],Res) :-
845 ((important_info(H); H=used_ids(_)) -> Res=[H|ET], extract_imp_info1(T,ET)
846 ; extract_imp_info1(T,Res)
847 ).
848
849 % extract and merge important info and try to merge used_ids from two info lists
850 merge_imp_info2(Info1,Info2,ResInfos) :-
851 extract_imp_info1(Info1,I1),
852 ? extract_imp_info1(Info2,I2),
853 merge_aux(I1,I2,ResInfos).
854
855 merge_aux([],I2,Res) :- !, delete(I2,used_ids(_),Res). % used_ids not valid for new construct
856 merge_aux(I1,[],Res) :- !, delete(I1,used_ids(_),Res). % ditto
857 merge_aux(I1,I2,ResInfos) :-
858 ? (select(used_ids(Ids1),I1,II1)
859 ? -> (select(used_ids(Ids2),I2,II2)
860 -> ord_union(Ids1,Ids2,Ids3),
861 append(II1,[used_ids(Ids3)|II2],II)
862 ; append(II1,I2,II)
863 )
864 ; delete(I2,used_ids(_),II2),
865 append(I1,II2,II)
866 ),
867 sort(II,ResInfos). % TO DO: sort sublists ? and use ord_union?
868
869 important_info(contains_wd_condition).
870 important_info(prob_annotation(_)).
871 important_info(allow_to_lift_exists).
872 important_info(removed_typing).
873 %important_info(lambda_result(_)). % should probably not be copied
874
875 % variation of above which does not extract and merge used_ids:
876 extract_just_important_info_aux([],Acc,Acc).
877 extract_just_important_info_aux([H|T],Acc,Res) :-
878 ? (important_info(H), \+ member(H,Acc) -> extract_just_important_info_aux(T,[H|Acc],Res)
879 ; extract_just_important_info_aux(T,Acc,Res)).
880
881
882 is_a_conjunct(b(conjunct(A,B),pred,_),A,B).
883 % use is_a_conjunct_without_label if you want to avoid decomposing conjunction associated with a single label
884 is_a_conjunct_without_label(b(conjunct(A,B),pred,I),A,B) :- \+ get_info_labels(I,_).
885 % use decompose conjunct if you want to propagate labels down to the conjuncts
886 decompose_conjunct(b(conjunct(A,B),pred,I),ResA,ResB) :-
887 ? (get_info_labels(I,Labels)
888 -> add_labels_to_texpr(A,Labels,ResA), add_labels_to_texpr(B,Labels,ResB)
889 ; ResA=A, ResB=B).
890
891 size_of_conjunction(C,Size) :- size_of_conjunction(C,0,Size).
892 size_of_conjunction(C,Acc,Res) :- is_a_conjunct(C,A,B),!,
893 size_of_conjunction(B,Acc,A1),
894 size_of_conjunction(A,A1,Res).
895 size_of_conjunction(_,Acc,Size) :- Size is Acc+1.
896
897 conjunction_to_list(C,L) :- var(C),!,
898 add_error_fail(conjunction_to_list,'Internal error: var :',conjunction_to_list(C,L)).
899 conjunction_to_list(C,List) :-
900 conjunction_to_list2(C,List,[]).
901 conjunction_to_list2(X,I,O) :- X=b(E,_,_),
902 (E=conjunct(LHS,RHS) -> conjunction_to_list2(LHS,I,Inter),
903 conjunction_to_list2(RHS,Inter,O)
904 ; E = truth -> I=O
905 ; I = [X|O]).
906
907 % a variation of conjunction_to_list which propagates Rodin and pragma label infos down
908 % important for proof info; maybe we should only propagate Rodin labels ?
909 conjunction_to_list_with_rodin_labels(C,L) :- var(C),!,
910 add_error_fail(conjunction_to_list,'Internal error: var :',conjunction_to_list_with_rodin_labels(C,L)).
911 conjunction_to_list_with_rodin_labels(C,List) :-
912 conjunction_to_list_with_labels2(C,List,[]).
913 conjunction_to_list_with_labels2(b(conjunct(A,B),pred,Infos),I,O) :- !,
914 copy_rodin_label(Infos,A,B,LHS,RHS),
915 conjunction_to_list_with_labels2(LHS,I,Inter),
916 conjunction_to_list_with_labels2(RHS,Inter,O).
917 conjunction_to_list_with_labels2(X,I,O) :- X=b(E,_,_),
918 ( E = truth -> I=O
919 ; I = [X|O]).
920
921
922 ?copy_rodin_label(Infos,A,B,NewA,NewB) :- member(Pos,Infos), is_rodin_label_info(Pos),!,
923 add_rodin_label_info(A,Pos,NewA),
924 add_rodin_label_info(B,Pos,NewB).
925 copy_rodin_label(_,A,B,A,B).
926
927 add_rodin_label_info(b(E,T,I),Pos,b(E,T,I2)) :-
928 (member(Pos,I), is_rodin_label_info(Pos) -> I2=I
929 ; I2 = [Pos|I]).
930
931 is_rodin_label_info(nodeid(Pos)) :- functor(Pos,rodinpos,_).
932
933
934 flatten_conjunctions(List,FlattenedList) :- flatten_conj_aux(List,FlattenedList,[]).
935 flatten_conj_aux([]) --> !, [].
936 flatten_conj_aux([H|T]) --> !, flatten_conj_aux(H),flatten_conj_aux(T).
937 flatten_conj_aux(C) --> {is_a_conjunct(C,LHS,RHS)},
938 !,
939 flatten_conj_aux(LHS), flatten_conj_aux(RHS).
940 flatten_conj_aux(Truth) --> {is_truth(Truth)},!,[].
941 flatten_conj_aux(C) --> [C].
942
943 member_in_conjunction(M,Conj) :- is_a_conjunct(Conj,LHS,RHS),!,
944 ? (member_in_conjunction(M,LHS) ; member_in_conjunction(M,RHS)).
945 member_in_conjunction(M,M).
946
947 % a version of member_in_conjunction which can deal with lazy_let_pred :
948 % member_in_conjunction_cse(FullConjunctWithLets,InnerConjunctNotALet, Conjunction)
949 member_in_conjunction_cse(M,InnerConj,Conj) :- is_a_conjunct(Conj,LHS,RHS),!,
950 (member_in_conjunction_cse(M,InnerConj,LHS) ; member_in_conjunction_cse(M,InnerConj,RHS)).
951 member_in_conjunction_cse(Conj,InnerConj,b(lazy_let_pred(ID,Share,Body),pred,Info)) :-
952 Conj = b(lazy_let_pred(ID,Share,BConj),pred,Info),!,
953 member_in_conjunction_cse(BConj,InnerConj,Body).
954 member_in_conjunction_cse(M,M,M).
955
956 % not terribly efficient way to select and remove a conjunct from a predicate
957 select_member_in_conjunction(M,Conj,Rest) :- is_a_conjunct(Conj,LHS,RHS),!,
958 ? (select_member_in_conjunction(M,LHS,RL), conjunct_predicates([RL,RHS],Rest)
959 ; select_member_in_conjunction(M,RHS,RR), conjunct_predicates([LHS,RR],Rest)).
960 select_member_in_conjunction(M,M,b(truth,pred,[])).
961
962 is_a_disjunct(b(disjunct(A,B),pred,_),A,B).
963 is_a_negation(b(negation(A),pred,_),A).
964
965 disjunction_to_list(C,L) :- var(C),!,
966 add_error_fail(disjunction_to_list,'Internal error: var :',disjunction_to_list(C,L)).
967 disjunction_to_list(C,List) :-
968 disjunction_to_list2(C,List,[]).
969 disjunction_to_list2(C,I,O) :- is_a_disjunct(C,LHS,RHS),!,
970 disjunction_to_list2(LHS,I,Inter),
971 disjunction_to_list2(RHS,Inter,O).
972 disjunction_to_list2(X,[X|R],R).
973
974 is_an_implication(b(implication(A,B),pred,_),A,B).
975
976 is_an_equivalence(b(equivalence(A,B),pred,_),A,B).
977
978
979 is_a_disjunct_or_implication(b(DI,pred,_),Type,A,B) :- is_a_disj_or_impl_aux(DI,Type,A,B).
980 is_a_disj_or_impl_aux(disjunct(A,B),'disjunction',A,B).
981 is_a_disj_or_impl_aux(implication(A,B),'implication',NA,B) :-
982 create_negation(A,NA).
983 is_a_disj_or_impl_aux(negation(b(conjunct(A,B),pred,_)),'negated conjunction',NA,NB) :-
984 create_negation(A,NA),create_negation(B,NB).
985
986 % a more liberal version of is_a_conjunct/2 which also detects negated disjunctions/implications
987 is_a_conjunct_or_neg_disj(b(DI,pred,I),A,B) :- is_conjunct_aux(DI,I,A,B).
988
989 is_conjunct_aux(conjunct(LHS,RHS),_,LHS,RHS).
990 is_conjunct_aux(negation(DISJ),_,NegLHS,NegRHS) :-
991 is_a_disjunct_or_implication(DISJ,_Type,LHS,RHS),
992 create_negation(LHS,NegLHS),
993 create_negation(RHS,NegRHS).
994 is_conjunct_aux(equal(TA,TB),I,b(equal(TA1,TB1),pred,I),b(equal(TA2,TB2),pred,I)) :-
995 % split TA1|->TA2 = TB1|->TB2, cf, split_equality/3; useful for enumeration order analysis
996 get_texpr_couple(TA,TA1,TA2),
997 get_texpr_couple(TB,TB1,TB2).
998 % print('Splitting equality in is_a_conjunct_or_neg_disj: '), translate:print_bexpr(b(equal(TA,TB),pred,I)),nl.
999
1000 %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
1001 % remove all info fields by fresh variables
1002 % typically the result will be unified with AST terms which contain full info fields
1003 remove_all_infos(TExpr,TNExpr) :-
1004 var(TExpr),!,TExpr=TNExpr.
1005 % in contrast to remove_all_infos_and_ground we provide no special treatment of values with closures here;
1006 % there could be a problem if we unify with a free variable as value
1007 remove_all_infos(TExpr,TNExpr) :-
1008 get_texpr_expr(TExpr,Expr),
1009 get_texpr_type(TExpr,Type),
1010 ? syntaxtransformation(Expr,Subs,_,NSubs,NExpr),
1011 create_texpr(NExpr,Type,_,TNExpr),
1012 ? maplist(remove_all_infos,Subs,NSubs).
1013
1014 % replace all info fields
1015 remove_all_infos_and_ground(TExpr,TNExpr) :-
1016 var(TExpr),!,TExpr=TNExpr.
1017 remove_all_infos_and_ground(b(value(Value),Type,_),TNExpr) :-
1018 % special case for closure(_,_,_) since it is not covered by syntraxtransformation/5
1019 % most useful for intervals
1020 !,
1021 remove_all_infos_from_bvalue(Value,NValue),
1022 TNExpr = b(value(NValue),Type,[]).
1023 remove_all_infos_and_ground(TExpr,TNExpr) :-
1024 get_texpr_expr(TExpr,Expr),
1025 get_texpr_type(TExpr,Type),
1026 syntaxtransformation(Expr,Subs,_,NSubs,NExpr),
1027 create_texpr(NExpr,Type,[],TNExpr),
1028 maplist(remove_all_infos_and_ground,Subs,NSubs).
1029
1030 remove_all_infos_from_bvalue(Var,Res) :- var(Var),!, Res=Var.
1031 remove_all_infos_from_bvalue((A,B),(RA,RB)) :- !,
1032 remove_all_infos_from_bvalue(A,RA),
1033 remove_all_infos_from_bvalue(B,RB).
1034 remove_all_infos_from_bvalue(closure(P,T,Body),Res) :- !,
1035 remove_all_infos_and_ground(Body,RBody),
1036 Res = closure(P,T,RBody).
1037 % TODO: we could provide more cases like records, sets as lists, freetype values
1038 remove_all_infos_from_bvalue(Val,Val).
1039
1040 %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
1041
1042 % a version of create_exists_opt which also detects top-level disjunctions
1043 % and marks the exists as generated and as allow_to_lift_exists
1044 create_exists_opt_liftable(Ids,b(disjunct(A,B),pred,Info1),NewPred) :- !,
1045 create_exists_opt_liftable(Ids,A,PA),
1046 create_exists_opt_liftable(Ids,B,PB),
1047 disjunct_predicates_with_pos_info(PA,PB,b(NP,pred,Info2)),
1048 NewPred=b(NP,pred,NewInfo),
1049 extract_just_important_info_aux(Info1,Info2,NewInfo). % copy symbolic or other relevant info
1050 create_exists_opt_liftable(Ids,Pred,NewPred) :- conjunction_to_list(Pred,L),
1051 create_exists_opt(Ids,L,[allow_to_lift_exists],NewPred,_Modified).
1052
1053 % create_exists_opt(TIds,Preds,NewPred)
1054 % creating an existential quantification with some optimisations.
1055 % TIds: The typed identifiers that are quantified
1056 % Preds: A list of predicates
1057 % NewPred: The (optimised) quantified expression
1058 % Basically two optimisations are performed:
1059 % - identifiers that are not used at all are removed from the quantifier
1060 % - predicates that do not use one of the quantified identifiers are moved
1061 % outside the quantification, resulting in a predicate of the form "P & #x.Q(x)"
1062
1063 create_exists_opt(TIds,Preds,NewPred) :-
1064 create_exists_opt(TIds,Preds,[],NewPred,_).
1065
1066 create_exists_opt(TIds,Preds,NewPred,Modified) :-
1067 create_exists_opt(TIds,Preds,[],NewPred,Modified).
1068
1069 create_exists_opt([],Preds,_,NewPred,Modified) :- !, Modified = false,
1070 conjunct_predicates(Preds,NewPred).
1071 create_exists_opt(TIds,Preds,AdditionalInfos,Res,Mod) :-
1072 get_texpr_ids(TIds,UnsortedIds), sort(UnsortedIds,Ids),
1073 (create_exists_opt1(TIds,Ids,Preds,AdditionalInfos,NewPred2,Modified) -> Res = NewPred2, Mod=Modified
1074 ; add_internal_error('Call failed:',create_exists_opt(TIds,Preds,AdditionalInfos,_,_)),fail).
1075 %create_exists_opt1(TIds,_,Preds,AdditionalInfos,NewPred,Modified) :- preference(data_validation_mode,true),
1076 % % do not lift predicates outside of existential quantifiers and change order; see rule_avec_DV.mch ClearSy example (N_ITERa_avec_DV_sans_DV) and test 1945
1077 create_exists_opt1(TIds,Ids,Preds,AdditionalInfos,NewPred2,Modified) :-
1078 create_exists_opt2(Preds,first,Ids,[],Inner,Outer,UsedIds),
1079 % Inner: quantified part, Outer: part which does not have to be quantified
1080 ( Inner = [] -> AllPreds=Outer % no exists needed
1081 ; % Inner = [_|_] ->
1082 create_filtered_exists(TIds,UsedIds,Inner,AdditionalInfos,Exists,IModified),
1083 append(Outer,[Exists],AllPreds)
1084 ),
1085 (Outer=[_|_] -> Modified=true % TO DO: check if TIds=UsedTIds
1086 ; IModified==true -> Modified=true
1087 ; UsedIds == Ids -> Modified= false
1088 ; Modified=true),
1089 conjunct_predicates(AllPreds,NewPred2).
1090
1091 % create an exists for the used Ids only
1092 create_filtered_exists(TIds,UsedIds,Inner,AdditionalInfos,Exists,_) :-
1093 ceo_filter_used_ids(TIds,UsedIds,UsedTIds), % filter out unused variables
1094 conjunct_predicates_with_pos_info(Inner,I), % we could store used_ids info
1095 create_exists_detect_tautology_aux(UsedTIds,I,AdditionalInfos,Exists).
1096 % remove_typing also added in create_exists_detect_tautology_aux
1097
1098
1099 % return Inner: predicates inside quantifier and Outer: predicates that can be moved out of the quantifier
1100 create_exists_opt2([],_,_Ids,UsedIds,[],[],UsedIds) :- !.
1101 create_exists_opt2([Pred|Prest],First,Ids,UsedIdsIn,Inner,Outer,UsedIdsOut) :- !,
1102 find_identifier_uses_if_necessary(Pred, [], LocalUses), % TODO: add used_ids(LocalUses) to Pred
1103 ord_intersection(Ids,LocalUses,ExistsIdsUsed),
1104 ( ExistsIdsUsed = [], % Pred uses none of the quantified ids: we can move it out
1105 (First==first -> true
1106 ; preference(data_validation_mode,false), % see test 1945; step 39 in trace replay
1107 always_well_defined_or_disprover_mode(Pred) % TODO: we should probably also check this !
1108 )
1109 ->
1110 Inner = Irest,
1111 Outer = [Pred|Orest], % move Pred out of existential quantifier as it does not depend on quantified variables
1112 % format('MOVED out of #(~w): ',[Ids]),translate:print_bexpr(Pred), format(' Uses ~w [~w]~n',[LocalUses,ExistsIdsUsed]),
1113 create_exists_opt2(Prest,first,Ids,UsedIdsIn,Irest,Orest,UsedIdsOut)
1114 ;
1115 update_used_ids(Pred,LocalUses,Pred2),
1116 Inner = [Pred2|Irest],
1117 Outer = Orest,
1118 ord_union(UsedIdsIn,ExistsIdsUsed,Urest),
1119 create_exists_opt2(Prest,not_first_anymore,Ids,Urest,Irest,Orest,UsedIdsOut)
1120 ).
1121 create_exists_opt2(Pred,First,Ids,UsedIdsIn,Inner,Outer,UsedIdsOut) :-
1122 add_error(create_exists_opt,'Expecting predicate list: ',Pred),
1123 create_exists_opt2([Pred],First,Ids,UsedIdsIn,Inner,Outer,UsedIdsOut).
1124
1125 % construct exists optimized: keep only used TIds
1126 ceo_filter_used_ids([],_UsedIds,[]).
1127 ceo_filter_used_ids([TId|Irest],UsedIds,Filtered) :-
1128 get_texpr_id(TId,Id),
1129 ( ord_member(Id,UsedIds) -> Filtered = [TId|Frest] % id used: keep it
1130 ; Filtered = Frest),
1131 ceo_filter_used_ids(Irest,UsedIds,Frest).
1132
1133 % a version of create_exists which also detects x=E and x:E, x>E, not(x>E) tautologies
1134 % we could replace this by a more generic prover
1135 create_exists_detect_tautology_aux([TID],b(member(LHS,RHS),pred,_),_,Truth) :-
1136 get_texpr_id(LHS,ID), get_texpr_id(TID,ID),
1137 definitely_not_empty_set(RHS),
1138 always_well_defined_or_disprover_mode(RHS),
1139 !, % replace #x.(x:RHS) by TRUTH
1140 debug_format(19,'Detected tautology exists membership over ~w~n',[ID]),
1141 Truth=b(truth,pred,[]).
1142 create_exists_detect_tautology_aux([TID],b(Pred,_,_),_,Truth) :-
1143 ? is_comparison(Pred,pos_neg(pos,TID),L,R), get_texpr_id(TID,ID),
1144 ((LHS,RHS)=(L,R) ; (LHS,RHS)=(R,L)),
1145 get_texpr_id(LHS,ID),
1146 \+ occurs_in_expr(ID,RHS),
1147 always_well_defined_or_disprover_mode(RHS),
1148 !, % replace #x.(x COMP E) by TRUTH
1149 debug_format(19,'Detected tautology comparison over ~w~n',[ID]),
1150 Truth=b(truth,pred,[]).
1151 %create_exists_detect_tautology_aux(Ids,b(disjunct(A,B),pred,Info1),AdditionalInfos,NewPred) :- !,
1152 % create_exists(Ids,A,PA), create_exists(Ids,B,PB),
1153 % disjunct_predicates_with_pos_info(PA,PB,b(NP,pred,Info2)),
1154 % NewPred=b(NP,pred,NewInfo),
1155 % extract_just_important_info_aux(Info1,Info2,NewInfo). % copy symbolic or other relevant info
1156 create_exists_detect_tautology_aux(Ids,Pred,AdditionalInfos,NewPred2) :-
1157 create_exists_or_let_predicate(Ids,Pred,NewPred),
1158 add_texpr_infos_if_new(NewPred,[removed_typing|AdditionalInfos],NewPred2).
1159 % removed_typing to avoid spurious exists_body_warning, see test 1681, 625
1160
1161
1162 is_eventb_comprehension_set(b(comprehension_set(TopIds,Body),_,Info),Ids,PRED,EXPR) :-
1163 ? is_eventb_comprehension_set(TopIds,Body,Info,Ids,PRED,EXPR).
1164 is_eventb_comprehension_set([TID1],Body,Info,Ids,PRED,EXPR) :-
1165 Body = b(exists(Ids,InnerBody),pred,_),
1166 conjunction_to_list(InnerBody,Inner),
1167 append(Inner1,[b(equal(TID2,EXPR),pred,EqInfo)],Inner),
1168 ? (member(was(event_b_comprehension_set),Info) -> true ;
1169 ? member(prob_annotation('LAMBDA-EQUALITY'),EqInfo) % relevant for TLA2B
1170 ),
1171 same_id(TID1,TID2,_),
1172 conjunct_predicates(Inner1,PRED),
1173 % we check that TID1 is not being used in P1 and not just rely on was(event_b_comprehension_set)
1174 not_occurs_in_expr(PRED,TID1).
1175
1176 % -------------------
1177
1178 is_equal(b(equal(LHS,RHS),pred,_),A,B) :-
1179 ((A,B)=(LHS,RHS) ; (A,B)=(RHS,LHS)).
1180
1181 :- use_module(typing_tools,[type_has_at_least_two_elements/1]).
1182 is_comparison(greater(A,B),_,A,B).
1183 is_comparison(less(A,B),_,A,B).
1184 is_comparison(greater_equal(A,B),_,A,B).
1185 is_comparison(less_equal(A,B),_,A,B).
1186 is_comparison(equal(A,B),pos_neg(P,TID),A,B) :-
1187 % for neg: we need to make sure there is more than one value in the type (otherwise we cannot make equal false)
1188 % for pos: assuming the RHS expression above is well-defined there must be at least one element; no need to check non_empty_type(Type)
1189 (P=pos -> true ; get_texpr_type(TID,Type),type_has_at_least_two_elements(Type)).
1190 is_comparison(not_equal(A,B),pos_neg(P,TID),A,B) :- % ditto but with pos and neg reversed
1191 (P=neg -> true ; get_texpr_type(TID,Type),type_has_at_least_two_elements(Type)).
1192 ?is_comparison(negation(b(Comp,pred,_)),PosNeg,A,B) :- negate(PosNeg,P2),
1193 is_comparison(Comp,P2,A,B).
1194 negate(pos_neg(pos,T),pos_neg(neg,T)).
1195 negate(pos_neg(neg,T),pos_neg(pos,T)).
1196
1197
1198
1199 % is true if a predicate Pred can be split into two parts:
1200 % Outer which does not depend on LocalIds (can be lifted out) and Inner which does
1201 detect_global_predicates(LocalIds,Pred,Outer,Inner) :-
1202 get_texpr_ids(LocalIds,UnsortedIds), sort(UnsortedIds,Ids),
1203 conjunction_to_list(Pred,Preds),
1204 split_predicate_local_global(Preds,Ids,OuterL,InnerL),
1205 OuterL \= [],
1206 conjunct_predicates(OuterL,Outer),
1207 conjunct_predicates(InnerL,Inner).
1208 split_predicate_local_global([],_Ids,[],[]).
1209 split_predicate_local_global([P|Ps],Ids,Outer,Inner) :-
1210 (is_local_predicate(Ids,P)
1211 -> Inner = [P|Is], split_predicate_local_global(Ps,Ids,Outer,Is)
1212 ; Outer = [P|Os], split_predicate_local_global(Ps,Ids,Os,Inner)).
1213 is_local_predicate(Ids,Pred) :-
1214 find_identifier_uses_if_necessary(Pred, [], LocalUses),
1215 ord_intersect(Ids,LocalUses).
1216
1217 %:- use_module(b_global_sets,[b_global_set/1]).
1218 definitely_not_empty_set(b(SET,T,_)) :- not_empty_set_aux(SET,T).
1219 not_empty_set_aux(bool_set,_).
1220 not_empty_set_aux(integer_set(_),_).
1221 not_empty_set_aux(float_set,_).
1222 not_empty_set_aux(real_set,_).
1223 not_empty_set_aux(string_set,_).
1224 not_empty_set_aux(set_extension(X),_) :- dif(X,[]).
1225 not_empty_set_aux(sequence_extension(X),_) :- dif(X,[]).
1226 not_empty_set_aux(pow_subset(_),_). % always contains at least the empty set
1227 not_empty_set_aux(fin_subset(_),_). % ditto
1228 not_empty_set_aux(seq(_),_). % ditto
1229 not_empty_set_aux(iseq(_),_). % ditto
1230 not_empty_set_aux(pow1_subset(A),_) :- definitely_not_empty_set(A).
1231 not_empty_set_aux(fin1_subset(A),_) :- definitely_not_empty_set(A).
1232 not_empty_set_aux(seq1(A),_) :- definitely_not_empty_set(A).
1233 not_empty_set_aux(iseq1(A),_) :- definitely_not_empty_set(A).
1234 not_empty_set_aux(cartesian_product(A,B),_) :- definitely_not_empty_set(A), definitely_not_empty_set(B).
1235 not_empty_set_aux(partial_function(_A,_B),_). % always contains at least the empty set
1236 not_empty_set_aux(partial_injection(_A,_B),_). % ditto
1237 not_empty_set_aux(relations(_A,_B),_). % ditto
1238 not_empty_set_aux(total_function(A,B),_) :-
1239 (definitely_not_empty_set(B) -> true
1240 ; definitely_empty_set(A)). % if A is empty, then the set of total functions is {{}}
1241 not_empty_set_aux(union(A,B),_) :- (definitely_not_empty_set(A) -> true ; definitely_not_empty_set(B)).
1242 not_empty_set_aux(overwrite(A,B),_) :- (definitely_not_empty_set(A) -> true ; definitely_not_empty_set(B)).
1243 % TODO: add a few more function rules
1244 not_empty_set_aux(value(S),_) :- not_empty_value(S).
1245 %not_empty_set_aux(identifier(X),set(global(X))) :- bmachine:b_get_machine_set(X). % what if we have a local variable ? ENSURE THAT WE DO NOT ALLOW identifier X to stand for global set X; see ExistentialGlobalSetIDTest in Tester % also: b_global_set not yet computed when ast_cleanup runs on startup !
1246 % TO DO: determine which identifier(X) refer to global set names
1247 not_empty_set_aux(interval(A,B),_) :- get_integer(A,IA), get_integer(B,IB), IA =< IB.
1248
1249 :- use_module(b_global_sets,[b_non_empty_global_set/1]).
1250 :- use_module(kernel_freetypes,[is_non_empty_freetype/1]).
1251 not_empty_value(S) :- var(S),!,fail.
1252 not_empty_value(avl_set(_)).
1253 not_empty_value([_|_]).
1254 not_empty_value(global_set(G)) :- b_non_empty_global_set(G). % always true
1255 not_empty_value(freetype(G)) :- is_non_empty_freetype(G). % always true
1256 not_empty_value(closure(P,T,B)) :-
1257 custom_explicit_sets:is_interval_closure(P,T,B,LOW,UP), integer(LOW),integer(UP), LOW =< UP.
1258 %TODO: more closures; see also definitely_not_empty_finite_value
1259
1260 definitely_empty_set(b(ES,_,_)) :- is_empty_set_aux(ES).
1261 is_empty_set_aux(empty_set).
1262 is_empty_set_aux(empty_sequence).
1263 is_empty_set_aux(domain(D)) :- definitely_empty_set(D).
1264 is_empty_set_aux(range(D)) :- definitely_empty_set(D).
1265 is_empty_set_aux(domain_subtraction(_,Rel)) :- definitely_empty_set(Rel).
1266 is_empty_set_aux(domain_restriction(Dom,Rel)) :- (definitely_empty_set(Dom) -> true ; definitely_empty_set(Rel)).
1267 is_empty_set_aux(range_restriction(Rel,Ran)) :- (definitely_empty_set(Ran) -> true ; definitely_empty_set(Rel)).
1268 is_empty_set_aux(range_subtraction(Rel,_)) :- definitely_empty_set(Rel).
1269 is_empty_set_aux(interval(A,B)) :- get_integer(A,IA), get_integer(B,IB), IA > IB.
1270 is_empty_set_aux(intersection(A,B)) :- (definitely_empty_set(A) -> true ; definitely_empty_set(B)).
1271 is_empty_set_aux(set_subtraction(A,_)) :- definitely_empty_set(A).
1272 is_empty_set_aux(union(A,B)) :- definitely_empty_set(A), definitely_empty_set(B).
1273 is_empty_set_aux(overwrite(A,B)) :- definitely_empty_set(A), definitely_empty_set(B).
1274 is_empty_set_aux(value(V)) :- V==[].
1275
1276
1277 get_integer(b(B,_,_),I) :- get_integer_aux(B,I).
1278 get_integer_aux(integer(I),I).
1279 get_integer_aux(value(V),I) :- get_integer_value(V,I).
1280 get_integer_value(V,I) :- nonvar(V),V=int(I), integer(I).
1281
1282
1283
1284 :- use_module(probsrc(custom_explicit_sets),[avl_is_interval/3]).
1285 get_interval(b(I,set(integer),_),Low,Up) :-
1286 is_interval_aux(I,Low,Up).
1287 is_interval_aux(interval(Low,Up),Low,Up).
1288 is_interval_aux(value(CS),Low,Up) :- nonvar(CS), CS=avl_set(AVL), % occurs in Leftpad_i.imp
1289 Low = b(integer(LI),integer,[]), Up = b(integer(UI),integer,[]),
1290 avl_is_interval(AVL,LI,UI).
1291 is_interval_aux(set_extension(List),Low,Up) :- print(l(List)),nl,
1292 sort(List,SList),
1293 SList = [Low|Rest], get_integer(Low,LI),
1294 last(SList,Up), get_integer(Up,UI),
1295 length(List,Len),
1296 Len is UI-LI+1,
1297 maplist(get_integer,Rest,_).
1298
1299 % a simple let-detection
1300 create_exists_or_let_predicate([H|T],b(conjunct(LHS,RHS),pred,I),NewPred) :- get_texpr_id(H,ID),
1301 ? is_equal(LHS,TID,IDEXPR), % TO DO: should we do a more complicated check here ? exist technique useful for SLOT-24 codespeed test
1302 get_texpr_id(TID,ID), \+ occurs_in_expr(ID,IDEXPR),
1303 maplist(not_occurs_in_expr(IDEXPR),T),
1304 !,
1305 NewPred = b(let_predicate([TID],[IDEXPR],Body),pred,I),
1306 %print('LET: '),translate:print_bexpr(NewPred),nl,
1307 create_exists_or_let_predicate(T,RHS,Body).
1308 create_exists_or_let_predicate(Ids,Pred,NewPred) :- create_exists(Ids,Pred,NewPred).
1309
1310 not_occurs_in_expr(IDEXPR,TID) :- get_texpr_id(TID,ID), \+ occurs_in_expr(ID,IDEXPR).
1311
1312 create_exists([],Pred,NewPred) :- !,Pred=NewPred.
1313 create_exists(Ids,Pred,NewPred) :-
1314 find_identifier_uses_for_quantifier_body(Ids,Pred, Used),
1315 extract_info_wo_used_ids(Pred,NewImportantInfo),
1316 create_texpr(exists(Ids,Pred),pred,[used_ids(Used)|NewImportantInfo],NewPred).
1317
1318 % try and infer seq(.) types for identifiers
1319 % at the moment this is a light-weight inference just using membership predicates
1320 infer_seq_types_for_tids([],_Pred,NewIds) :- !, NewIds=[].
1321 infer_seq_types_for_tids(Ids,Pred,NewIds) :-
1322 conjunction_to_list(Pred,LP),
1323 infer_seq_types_for_preds(LP,Ids,NewIds).
1324
1325 infer_seq_types_for_preds([],TIds,TIds).
1326 infer_seq_types_for_preds([H|T],TIds,NewTIds) :-
1327 infer_seq_type_for_id(H,Id,NewType),
1328 debug_println(19,sequence_type_inferred_for(Id,NewType)),
1329 TID = b(identifier(Id),_OldType,Info),
1330 ? nth1(Pos,TIds,TID,Rest),
1331 get_texpr_id(TID,Id),!,
1332 nth1(Pos,NewTIds1,b(identifier(Id),NewType,Info),Rest),
1333 infer_seq_types_for_preds(T,NewTIds1,NewTIds).
1334 infer_seq_types_for_preds([b(LetPred,pred,_)|T],TIds,NewTIds) :- % see test 1377
1335 is_let_pred(LetPred,LetTIds,MainPred),
1336 % there should be no conflict between lazy let id @Nr and quantified variables; but we check nonetheless
1337 \+ clash(LetTIds,TIds),
1338 !,
1339 conjunction_to_list(MainPred,MainLP),
1340 infer_seq_types_for_preds(MainLP,TIds,TIds2), % TODO: store value of LazyLetID?
1341 infer_seq_types_for_preds(T,TIds2,NewTIds).
1342 infer_seq_types_for_preds([_|T],TIds,NewTIds) :- infer_seq_types_for_preds(T,TIds,NewTIds).
1343
1344 ?clash(TIds1,TIds2) :- member(TLazyID,TIds1),
1345 get_texpr_id(TLazyID,LazyID),
1346 % there should be no conflict between lazy let id @Nr and quantified variables; but we check nonetheless
1347 member(b(identifier(LazyID),_,_),TIds2).
1348 is_let_pred(lazy_let_pred(TLazyID,_SharedExpr,MainPred),[TLazyID],MainPred).
1349 is_let_pred(let_predicate(TIDs,_SharedExpr,MainPred),TIDs,MainPred).
1350
1351
1352 infer_seq_type_for_id(b(member(LHS,RHS),_,_),Id,Type) :-
1353 get_texpr_id(LHS,Id),
1354 is_seq_type_rhs(RHS,Type).
1355
1356 is_seq_type_rhs(b(E,T,_),seq(ResType)) :-
1357 ? T = set(SEQT), is_seq_type(SEQT,SType),
1358 is_seq_type_rhs2(E,SType,ResType).
1359 is_seq_type_rhs2(seq(Set),FullType,SeqType) :-
1360 (is_seq_type_rhs(Set,IS) -> SeqType=IS ; SeqType=FullType). % TODO: check if arguments also contain seq types
1361 is_seq_type_rhs2(iseq1(Set),FullType,S) :- is_seq_type_rhs2(seq(Set),FullType,S).
1362 is_seq_type_rhs2(iseq(Set),FullType,S) :- is_seq_type_rhs2(seq(Set),FullType,S).
1363 is_seq_type_rhs2(seq1(Set),FullType,S) :- is_seq_type_rhs2(seq(Set),FullType,S).
1364 is_seq_type_rhs2(perm(Set),FullType,S) :- is_seq_type_rhs2(seq(Set),FullType,S).
1365 is_seq_type_rhs2(value(V),_FullType,S) :- nonvar(V), V=closure([_],[seq(S)],_). % TODO: more than one arg
1366 % TODO: relations/functions/cartesian product with seq types
1367 % TODO: {x|x : seq((0 .. 1)) & card(x) > 5}, ...
1368
1369 is_seq_type(seq(S),S).
1370 is_seq_type(set(couple(integer,S)),S).
1371
1372 % a version of create_exists which can merge with an already present exists if possible
1373 % possibly more expensive as identfiers used are recomputed for the moment (TODO: reuse used_ids and subtract)
1374 create_or_merge_exists(IDs, Condition, Exists):-
1375 get_texpr_expr(Condition,exists(InnerVars,InnerCond)),!,
1376 % fuse two exists together
1377 append(IDs,InnerVars,Vars),
1378 create_or_merge_exists(Vars,InnerCond,Exists).
1379 create_or_merge_exists(IDs, Condition, Exists):-
1380 create_exists(IDs,Condition,Exists).
1381
1382 % see create_unsimplified_exists
1383 not_generated_exists_paras([b(_,_,Infos)|_]) :- nonmember(generated_exists_parameter,Infos).
1384
1385
1386 create_forall([],Pred,NewPred) :- !,Pred=NewPred.
1387 create_forall(Ids,Pred,NewPred) :-
1388 find_identifier_uses_for_quantifier_body(Ids,Pred, Used),
1389 split_forall_body(Pred,LHS,RHS),
1390 extract_info_wo_used_ids_and_pos(LHS,RHS,NewImportantInfo),
1391 infer_seq_types_for_tids(Ids,LHS,Ids2),
1392 create_texpr(forall(Ids2,LHS,RHS),pred,[used_ids(Used)|NewImportantInfo],NewPred).
1393 split_forall_body(b(implication(LHS,RHS),_,_),LHS,RHS) :- !.
1394 split_forall_body(RHS,b(truth,pred,[]),RHS).
1395
1396 create_implication(b(truth,pred,_),P,Res) :- !, Res=P.
1397 create_implication(b(falsity,pred,_),P,Res) :- !, create_negation(P,Res).
1398 create_implication(Lhs,Rhs,b(implication(Lhs,Rhs),pred,NewInfo)) :-
1399 extract_info(Lhs,Rhs,NewInfo).
1400
1401 create_equivalence(Lhs,Rhs, b(equivalence(Lhs,Rhs),pred,NewInfo)) :-
1402 extract_info(Lhs,Rhs,NewInfo).
1403
1404 create_negation(b(P,pred,I),Res) :- create_negation_aux(P,I,R),!,Res=R.
1405 create_negation(Pred,b(negation(Pred),pred,NewInfo)) :-
1406 extract_info(Pred,Infos),
1407 ? (get_texpr_non_label_posinfo(Pred,Pos) -> NewInfo = [Pos|Infos] ; NewInfo=Infos).
1408
1409 create_negation_aux(truth,I,R) :- !, R=b(falsity,pred,I).
1410 create_negation_aux(falsity,I,R) :- !, R=b(truth,pred,I).
1411 create_negation_aux(negation(Pred),_,R) :- R=Pred. % not(not(P)) = P
1412 %create_negation_aux(equal(A,B),I,R) :- !, R=b(not_equal(A,B),pred,I).
1413 %create_negation_aux(not_equal(A,B),I,R) :- !, R=b(equal(A,B),pred,I).
1414 % we could add some rules about negating member <-> not_member, ... but be careful with effects on is_negation_of
1415
1416 % check if something is the negation of something else (quite stupid at the moment)
1417 % used, e.g., to detect IF-THEN-ELSE constructs in b_ast_cleanup
1418 is_negation_of(P,NP) :-
1419 create_negation(P,NotP), % works both with not(A),A or A,not(A)
1420 same_texpr(NotP,NP).
1421 ?is_negation_of(b(P,pred,_),b(NP,pred,_)) :- is_negation_aux(P,NP).
1422
1423 ?is_negation_aux(equal(A,B),NP) :- is_negation_of_equality(NP,A,B).
1424 is_negation_aux(not_equal(A,B),NP) :- is_negation_of_disequality(NP,A,B).
1425 is_negation_aux(subset(XA,SA),not_subset(XB,SB)) :- same_texpr(XA,XB), same_texpr(SA,SB).
1426 is_negation_aux(not_subset(XA,SA),subset(XB,SB)) :- same_texpr(XA,XB), same_texpr(SA,SB).
1427 is_negation_aux(subset_strict(XA,SA),not_subset_strict(XB,SB)) :- same_texpr(XA,XB), same_texpr(SA,SB).
1428 is_negation_aux(not_subset_strict(XA,SA),subset_strict(XB,SB)) :- same_texpr(XA,XB), same_texpr(SA,SB).
1429 is_negation_aux(member(XA,SA),not_member(XB,SB)) :- same_texpr(XA,XB), same_texpr(SA,SB).
1430 is_negation_aux(not_member(XA,SA),member(XB,SB)) :- same_texpr(XA,XB), same_texpr(SA,SB).
1431 is_negation_aux(less(A,B),greater_equal(AA,BB)) :- same_texpr(A,AA), same_texpr(B,BB).
1432 is_negation_aux(less(A,B),less_equal(BB,AA)) :- same_texpr(A,AA), same_texpr(B,BB).
1433 is_negation_aux(less_equal(B,A),less(AA,BB)) :- same_texpr(A,AA), same_texpr(B,BB).
1434 is_negation_aux(less_equal(A,B),greater(AA,BB)) :- same_texpr(A,AA), same_texpr(B,BB).
1435 ?is_negation_aux(greater_equal(A,B),NP) :- is_negation_aux(less_equal(B,A),NP).
1436 is_negation_aux(greater(A,B),NP) :- is_negation_aux(less(B,A),NP).
1437 is_negation_aux(less_equal_real(B,A),less_real(AA,BB)) :- same_texpr(A,AA), same_texpr(B,BB).
1438 is_negation_aux(less_real(B,A),less_equal_real(AA,BB)) :- same_texpr(A,AA), same_texpr(B,BB).
1439 is_negation_aux(negation(A),negation(B)) :- is_negation_of(A,B).
1440 is_negation_aux(truth,falsity).
1441 is_negation_aux(falsity,truth).
1442 % TO DO: detect more ?? x < y <=> not ( x > y-1 )
1443
1444 is_negation_of_equality(not_equal(AA,BB),A,B) :- same_texpr(A,AA), same_texpr(B,BB).
1445 ?is_negation_of_equality(equal(AA,BB),A,B) :- same_texpr(A,AA), neg_value(BB,B).
1446
1447 neg_value(b(boolean_true,_,_),b(boolean_false,_,_)).
1448 neg_value(b(boolean_false,_,_),b(boolean_true,_,_)).
1449
1450 is_negation_of_disequality(equal(AA,BB),A,B) :- same_texpr(A,AA), same_texpr(B,BB).
1451 is_negation_of_disequality(not_equal(AA,BB),A,B) :- same_texpr(A,AA), neg_value(BB,B).
1452
1453
1454 % another version which is simpler can can be used to get the negation of some operators
1455
1456 get_negated_operator_expr(b(E,pred,_),Res) :- negate_expr_aux(E,Res).
1457 negate_expr_aux(falsity,truth).
1458 negate_expr_aux(truth,falsity).
1459 negate_expr_aux(member(X,S),not_member(X,S)).
1460 negate_expr_aux(not_member(X,S),member(X,S)).
1461 negate_expr_aux(subset(X,S),not_subset(X,S)).
1462 negate_expr_aux(not_subset(X,S),subset(X,S)).
1463 negate_expr_aux(subset_strict(X,S),not_subset_strict(X,S)).
1464 negate_expr_aux(not_subset_strict(X,S),subset_strict(X,S)).
1465 negate_expr_aux(equal(X,S),not_equal(X,S)).
1466 negate_expr_aux(not_equal(X,S),equal(X,S)).
1467 negate_expr_aux(less(X,S),greater_equal(X,S)).
1468 negate_expr_aux(greater_equal(X,S),less(X,S)).
1469 negate_expr_aux(less_equal(X,S),greater(X,S)).
1470 negate_expr_aux(greater(X,S),less_equal(X,S)).
1471 negate_expr_aux(less_equal_real(X,S),less_real(S,X)).
1472 negate_expr_aux(less_real(X,S),less_equal_real(S,X)).
1473 % TO DO: negation()
1474
1475
1476 % a liberal version for finding equalities
1477 is_equality(TP,TA,TB) :- get_texpr_expr(TP,P), is_equality_aux(P,TA,TB).
1478
1479 is_equality_aux(Var,TA,TB) :- var(Var),!, add_internal_error('Illegal call: ', is_equality_aux(Var,TA,TB)),fail.
1480 is_equality_aux(equal(TA,TB),TA,TB).
1481 is_equality_aux(not_equal(TA,TB),NTA,NTB) :-
1482 (negate_boolean_value(TB,NTB) -> NTA=TA
1483 ; NTB=TB, negate_boolean_value(TA,NTA)). % TA /= TRUE ---> TA = FALSE
1484 is_equality_aux(partition(TA,[TB]),TA,TB).
1485 is_equality_aux(member(TA,TSet),TA,TB) :- singleton_set_extension(TSet,TB). % TA:{TB}
1486 is_equality_aux(negation(TExpr),TA,TB) :- get_negated_operator_expr(TExpr,NT), is_equality_aux(NT,TA,TB).
1487
1488 negate_boolean_value(b(B,T,I),b(NB,T,I)) :- neg_bool_aux(B,NB).
1489 neg_bool_aux(boolean_true,boolean_false).
1490 neg_bool_aux(boolean_false,boolean_true).
1491 % TODO: should we also detect value(pred_true), ....
1492
1493 singleton_set_extension(b(SONE,Type,_),El) :- singleton_set_extension_aux(SONE,Type,El).
1494 singleton_set_extension_aux(set_extension([El]),_,El).
1495 singleton_set_extension_aux(value(Set),SType,b(value(El),Type,[])) :-
1496 is_set_type(SType,Type),custom_explicit_sets:singleton_set(Set,El).
1497 singleton_set_extension_aux(sequence_extension([El]),_,Couple) :-
1498 ONE = b(integer(1),integer,[]),
1499 create_couple(ONE,El,Couple).
1500
1501
1502 % detect various forms of membership:
1503 is_membership(b(Expr,pred,_),TID,Set) :- is_membership_aux(Expr,TID,Set).
1504 is_membership_aux(member(TID,Set),TID,Set).
1505 is_membership_aux(subset(SONE,Set),TID,Set) :- singleton_set_extension(SONE,TID). % {TID} <: Set
1506
1507 % detect even more forms of membership:
1508 is_membership_or_equality(b(Expr,pred,_),TID,Set) :-
1509 ? (is_membership_aux(Expr,TID,Set) -> true ; is_mem_eq_aux(Expr,TID,Set)).
1510
1511 is_mem_eq_aux(equal(TID,VAL),TID,Set) :- % x=VAL <==> x:{VAL}
1512 get_texpr_type(VAL,Type),
1513 safe_create_texpr(set_extension([VAL]),set(Type),Set).
1514
1515 % extract a lambda equality from a body; we suppose the equality is the last conjunct
1516 get_lambda_equality(b(equal(TID,ResultExpr),pred,_),ID,[],ResultExpr) :- get_texpr_id(TID,ID).
1517 get_lambda_equality(b(conjunct(LHS,RHS),pred,_),ID,[LHS|T],ResultExpr) :-
1518 ? get_lambda_equality(RHS,ID,T,ResultExpr).
1519
1520 % ---------------------------------
1521
1522 is_pow_subset(B,Set) :-
1523 ( B = b(pow_subset(Set),_,_)
1524 ; B = b(fin_subset(Set),_,_),
1525 finite_wd_set_value(Set)
1526 ).
1527 is_pow1_subset(B,Set) :-
1528 ( B = b(pow1_subset(Set),_,_)
1529 ; B = b(fin1_subset(Set),_,_),
1530 finite_wd_set_value(Set)
1531 ).
1532
1533 % ---------------------------------
1534
1535 get_texpr_couple(b(couple(TA1,TA2),_,_),TA1,TA2).
1536
1537 % detect TA1|->TA2 = TB1|->TB2 and split into two
1538 split_equality(b(equal(TA,TB),pred,I),b(equal(TA1,TB1),pred,I),b(equal(TA2,TB2),pred,I)) :-
1539 get_texpr_couple(TA,TA1,TA2),
1540 get_texpr_couple(TB,TB1,TB2).
1541
1542 create_equality(b(_,TA,_),b(_,TB,_),_) :- TA \= TB, \+ unify_types_strict(TA,TB),!,
1543 add_internal_error('Creating equality with incompatible types:',equal(TA,TB)),fail.
1544 create_equality(A,B,Equality) :-
1545 safe_create_texpr(equal(A,B),pred,Equality).
1546
1547 create_couple(A,B,b(couple(A,B),couple(TA,TB),Infos)) :-
1548 get_texpr_type(A,TA), get_texpr_type(B,TB),
1549 extract_info(A,B,Infos).
1550
1551 % couplise_list for typed expression list
1552 create_couple([A],Couple) :- !,A=Couple.
1553 create_couple([A,B|Rest],Couple) :-
1554 create_couple(A,B,Couple1),
1555 create_couple([Couple1|Rest],Couple).
1556
1557 create_cartesian_product(A,B,CartAB) :-
1558 get_texpr_types([A,B],[STA,STB]),
1559 is_set_type(STA,TypeA), is_set_type(STB,TypeB),
1560 safe_create_texpr(cartesian_product(A,B),set(couple(TypeA,TypeB)),CartAB).
1561
1562 % derive typing from Ids
1563 create_comprehension_set(Ids,Pred,Info,CompSet) :-
1564 get_texpr_types(Ids,Types),
1565 couplise_list(Types,ElementType),
1566 create_texpr(comprehension_set(Ids,Pred),set(ElementType),Info,CompSet).
1567
1568
1569 :- assert_must_succeed(bsyntaxtree:nested_couple_to_list(b(couple(b(couple(a,b),x,[]),c),xx,[]),[a,b,c])).
1570 :- assert_must_succeed(bsyntaxtree:nested_couple_to_list(b(couple(a,c),x,[]),[a,c])).
1571 :- assert_must_succeed(bsyntaxtree:nested_couple_to_list(b(couple(a,b(couple(b,c),x,[])),xx,[]),[a,b(couple(b,c),x,[])])).
1572 nested_couple_to_list(NC,L) :- nested_couple_to_list_dcg(NC,L,[]).
1573 nested_couple_to_list_dcg(b(couple(A,B),_,_)) --> !,
1574 nested_couple_to_list_dcg(A), [B].
1575 nested_couple_to_list_dcg(E) --> [E].
1576
1577 % --------------------------------------
1578
1579
1580 % check if identifier(s) occur in typed expressions
1581
1582 occurs_in_expr(ID,TExpr) :- var(ID),!,
1583 add_internal_error('Variable id: ',occurs_in_expr(ID,TExpr)),fail.
1584 occurs_in_expr(ID,TExpr) :- ID=b(_,_,_),!, add_internal_error('Non-atomic identifier: ',occurs_in_expr(ID,TExpr)),fail.
1585 occurs_in_expr(ID,TExpr) :- ID=[_|_],!,
1586 add_internal_error('List instead of identifier: ',occurs_in_expr(ID,TExpr)),fail.
1587 occurs_in_expr(ID,TExpr) :- occurs_in_expr1(TExpr,ID).
1588
1589 % treat a few common operators here; possibly avoid traversing whole term if we find ID in a sub-tree
1590 occurs_in_expr1(TExpr,ID) :- TExpr = b(Expr,_,_),!,
1591 occurs_in_expr2(Expr,TExpr,ID).
1592 occurs_in_expr1(TExpr,ID) :- add_internal_error('Illegal typed expression:',occurs_in_expr1(TExpr,ID)).
1593
1594 occurs_in_expr2(add(A,B),_,ID) :- !,
1595 (occurs_in_expr1(A,ID) -> true ; occurs_in_expr1(B,ID)).
1596 occurs_in_expr2(conjunct(A,B),_,ID) :- !,
1597 (occurs_in_expr1(A,ID) -> true ; occurs_in_expr1(B,ID)).
1598 occurs_in_expr2(couple(A,B),_,ID) :- !,
1599 (occurs_in_expr1(A,ID) -> true ; occurs_in_expr1(B,ID)).
1600 occurs_in_expr2(member(A,B),_,ID) :- !,
1601 (occurs_in_expr1(A,ID) -> true ; occurs_in_expr1(B,ID)).
1602 occurs_in_expr2(equal(A,B),_,ID) :- !,
1603 (occurs_in_expr1(A,ID) -> true ; occurs_in_expr1(B,ID)).
1604 occurs_in_expr2(function(A,B),_,ID) :- !,
1605 (occurs_in_expr1(A,ID) -> true ; occurs_in_expr1(B,ID)).
1606 occurs_in_expr2(image(A,B),_,ID) :- !,
1607 (occurs_in_expr1(A,ID) -> true ; occurs_in_expr1(B,ID)).
1608 occurs_in_expr2(intersection(A,B),_,ID) :- !,
1609 (occurs_in_expr1(A,ID) -> true ; occurs_in_expr1(B,ID)).
1610 occurs_in_expr2(interval(A,B),_,ID) :- !,
1611 (occurs_in_expr1(A,ID) -> true ; occurs_in_expr1(B,ID)).
1612 occurs_in_expr2(not_equal(A,B),_,ID) :- !,
1613 (occurs_in_expr1(A,ID) -> true ; occurs_in_expr1(B,ID)).
1614 occurs_in_expr2(assertion_expression(A,_Msg,B),_,ID) :- !,
1615 (occurs_in_expr1(A,ID) -> true ; occurs_in_expr1(B,ID)).
1616 occurs_in_expr2(domain(A),_,ID) :- !, occurs_in_expr1(A,ID).
1617 occurs_in_expr2(range(A),_,ID) :- !, occurs_in_expr1(A,ID).
1618 occurs_in_expr2(record_field(A,_FieldName),_,ID) :- !, occurs_in_expr1(A,ID).
1619 occurs_in_expr2(identifier(ID1),_,ID) :- !,
1620 ID1 = ID.
1621 occurs_in_expr2(integer(_),_,_ID) :- !,fail.
1622 occurs_in_expr2(string(_),_,_ID) :- !,fail.
1623 occurs_in_expr2(value(_),_,_ID) :- !,fail.
1624 occurs_in_expr2(truth,_,_ID) :- !,fail.
1625 occurs_in_expr2(if_then_else(A,B,C),_,ID) :- !,
1626 (occurs_in_expr1(A,ID) -> true ; occurs_in_expr1(B,ID) -> true ; occurs_in_expr1(C,ID)).
1627 occurs_in_expr2(rec(Fields),_,ID) :- !,
1628 l_field_occurs_in_expr1(Fields,ID).
1629 occurs_in_expr2(set_extension(Elements),_,ID) :- !,
1630 l_occurs_in_expr1(Elements,ID).
1631 occurs_in_expr2(sequence_extension(Elements),_,ID) :- !,
1632 l_occurs_in_expr1(Elements,ID).
1633 occurs_in_expr2(Expr,_,ID) :-
1634 syntaxelement(Expr,List,[], [], [], _), % no bound quantifiers; TO DO: treat bound quantifiers
1635 !,
1636 l_occurs_in_expr1(List,ID).
1637 occurs_in_expr2(_E,TExpr,ID) :-
1638 %functor(_E,F,N), print(occurs_in_expr2(F,N,ID)),nl,
1639 (find_identifier_uses_if_necessary(TExpr,[],Used)
1640 -> %check_sorted(Used),
1641 %add_message(bsyntaxtree,'Occurs check: ',ID:Used,TExpr), translate:nested_print_bexpr(TExpr),nl,
1642 ord_member(ID,Used)
1643 ; add_failed_call_error(find_identifier_uses(TExpr,[],_)),fail).
1644 % TO DO: optimize so that we only look for ID; we don't have to keep track of other IDs
1645
1646 l_occurs_in_expr1([H|T],ID) :- !,
1647 (occurs_in_expr1(H,ID) -> true ; l_occurs_in_expr1(T,ID)).
1648 l_occurs_in_expr1(L,ID) :- L \= [],
1649 add_internal_error('Illegal typed expression list:',l_occurs_in_expr1(L,ID)).
1650 l_field_occurs_in_expr1([field(_,H)|T],ID) :- !,
1651 (occurs_in_expr1(H,ID) -> true ; l_field_occurs_in_expr1(T,ID)).
1652 l_field_occurs_in_expr1(L,ID) :- L \= [],
1653 add_internal_error('Illegal record field list:',l_field_occurs_in_expr1(L,ID)).
1654
1655 %check_sorted(List) :- sort(List,SL), (SL \= List -> add_internal_error('Not sorted:',List) ; true).
1656
1657 some_id_occurs_in_expr([H|T],TExpr) :- (var(H) ; \+ atomic(H) ; var(T) ; T=[H2|_], H2 @< H),
1658 add_internal_error('Must be (sorted) atomic identifiers: ',some_id_occurs_in_expr([H|T],TExpr)),
1659 fail.
1660 some_id_occurs_in_expr([Id],TExpr) :- !, % use version without complete find_identifier_uses
1661 occurs_in_expr(Id,TExpr).
1662 some_id_occurs_in_expr(SortedIDs,TExpr) :-
1663 find_identifier_uses_if_necessary(TExpr,[],Used),
1664 list_to_ord_set(Used,UsedSorted),
1665 ord_intersect(UsedSorted,SortedIDs).
1666
1667 % -----------------------------
1668
1669 % find used identifiers in typed expressions
1670
1671 % a special version for quantifier bodies, attempting to reuse used_ids info
1672 find_identifier_uses_for_quantifier_body(TIds,Body,Res) :-
1673 get_texpr_ids(TIds,Ids),
1674 list_to_ord_set(Ids,Ignore),
1675 find_identifier_uses_if_necessary(Body,Ignore,Res).
1676
1677 % only run find_identifier_uses if necessary because no used_ids Info field present
1678 % TO DO: we could consider using used_ids within find_typed_identifier_uses: drawback: we would need to store types
1679 find_identifier_uses_if_necessary(Expr,Ignore,Res) :-
1680 get_texpr_info(Expr,I),
1681 ? member(used_ids(UIds),I),!, %print('+'),nl,
1682 find_with_reuse(Expr,UIds,Ignore,Res).
1683 find_identifier_uses_if_necessary(Expr,Ignore,Res) :- find_identifier_uses(Expr,Ignore,Res).
1684
1685 find_with_reuse(Expr,UIds,Ignore,Res) :- preference(prob_safe_mode,true),
1686 !,
1687 (is_ordset(Ignore) -> true ; add_internal_error('Not ordset: ',Ignore)),
1688 (is_ordset(UIds) -> true ; add_internal_error('Not ordset: ',UIds)),
1689 ord_subtract(UIds,Ignore,Res0),
1690 find_identifier_uses(Expr,Ignore,Res1),
1691 (Res1=Res0 -> true
1692 ; ord_subtract(Res1,Res0,Miss), % missing
1693 ord_subtract(Res0,Res1,Res01), % too much
1694 (Miss=[] -> add_message(find_identifier_uses_if_necessary,'Suboptimal used_ids: ',Res01,Expr)
1695 ; add_internal_error('Incorrect used_ids:',used_ids(missing(Miss),toomuch(Res01),usedids(UIds),
1696 ignore(Ignore),real(Res1))),
1697 translate:print_bexpr(Expr),nl
1698 )
1699 ),
1700 Res=Res1.
1701 find_with_reuse(_,UIds,Ignore,Res) :-
1702 %(is_ordset(Ignore) -> true ; add_internal_error('Not ordset: ',Ignore)),
1703 ord_subtract(UIds,Ignore,Res).
1704
1705
1706 find_identifier_uses_top_level(TExpr,Ids) :-
1707 % get_global_identifiers(Ignored), % ignore all global sets and global constants;
1708 % hence find_identifier_uses_top_level/2 usually should only be called for top level expressions
1709 Ignored = [], % much more efficient to exclude afterwards for long lists of Ignored ids
1710 find_identifier_uses(TExpr,Ignored,Ids0),
1711 exclude_global_identifiers(Ids0,Ids).
1712
1713 :- use_module(tools,[safe_sort/3]).
1714 find_identifier_uses(TExpr,Ignored,Ids) :-
1715 %tools_printing:print_term_summary(find_identifier_uses(TExpr,Ignored,Ids)),nl,
1716 check_is_texpr(TExpr,find_identifier_uses),
1717 (find_typed_identifier_uses(TExpr,Ignored,TIds)
1718 -> get_texpr_ids(TIds,RIds),
1719 % in case of type errors, or when type checking is not yet complete, we can have multiple entries of the same identifier with different types !
1720 sort(RIds,Ids) % was remove_dups, but remove_dups just calls sort; TODO: implement get_sorted_texpr_ids
1721 ; add_internal_error('Call failed:',find_typed_identifier_uses(TExpr,Ignored,_)),
1722 Ids=[]
1723 ).
1724 find_identifier_uses_l(TExprs,Ignored,Ids) :-
1725 find_typed_identifier_uses_l(TExprs,Ignored,TIds),
1726 get_texpr_ids(TIds,RIds),
1727 sort(RIds,Ids). % see above
1728
1729 check_is_texpr(X,Context) :-
1730 (get_texpr_expr(X,_) -> true ; add_internal_error('Expected TExpr: ', check_is_texpr(X,Context))).
1731
1732 find_typed_identifier_uses(TExpr,Ids) :-
1733 % get_global_identifiers(Ignored), % ignore all global sets and global constants; hence find_typed_identifier_uses/2 usually should only be called for top level expressions
1734 Ignored = [],
1735 find_typed_identifier_uses(TExpr,Ignored,Ids0),
1736 exclude_global_identifiers(Ids0,Ids).
1737
1738 find_typed_identifier_uses(TExpr,Ignored,Ids) :- var(TExpr),!,
1739 add_internal_error('Variable typed expression: ', find_typed_identifier_uses(TExpr,Ignored,Ids)),
1740 Ids = [].
1741 find_typed_identifier_uses(TExpr,Ignored,Ids) :-
1742 find_typed_identifier_uses_l([TExpr],Ignored,Ids).
1743
1744 find_typed_identifier_uses2(TExpr,Ignored,Ids,Rest) :-
1745 get_texpr_expr(TExpr,Expr),
1746 safe_syntaxelement_det(Expr,Subs,TNames,_,_), % QSubs=[],
1747 ( uses_an_identifier(Expr,Id,TExpr,Ignored) ->
1748 ( ord_member(Id,Ignored) -> Ids=Rest
1749 ;
1750 get_texpr_type(TExpr,Type),
1751 normalize_type(Type,NType), % replace seq by set;
1752 % warning: when type-check not yet complete we have variables here
1753 create_texpr(identifier(Id),NType,[],TId),
1754 %print(adding(Id,NType,Ignored)),nl,
1755 Ids = [TId|Rest]
1756 )
1757 % ; (Expr = becomes_such(TIds,_)), nl,print(uses_primes(Expr)),nl,fail
1758 ; indirectly_uses_identifiers(Expr,Ignored,IndirectIds) ->
1759 add_typed_ids(IndirectIds,Ids,Rest2),
1760 find_typed_identifier_uses2_l(Subs,Ignored,Rest2,Rest)
1761 ; TNames = [] -> find_typed_identifier_uses2_l(Subs,Ignored,Ids,Rest)
1762 ;
1763 %find_typed_identifier_uses2_l(QSubs,Ignored,Ids,Ids2), % useless here as QSubs=[]
1764 get_texpr_ids(TNames,Names),
1765 list_to_ord_set(Names,SNames), ord_union(SNames,Ignored,Ignored2),
1766 find_typed_identifier_uses2_l(Subs,Ignored2,Ids,Rest)).
1767 find_typed_identifier_uses2_l([],_) --> !, [].
1768 find_typed_identifier_uses2_l([Expr|Rest],Ignored) --> !,
1769 find_typed_identifier_uses2(Expr,Ignored),
1770 find_typed_identifier_uses2_l(Rest,Ignored).
1771 find_typed_identifier_uses2_l(E,Ignored) -->
1772 {add_internal_error('Illegal arguments (not a list):',find_typed_identifier_uses2_l(E,Ignored)),fail}.
1773
1774 %Note: above we do not remap uses of Id$0 to Id in becomes_such;
1775 % this is done in find_read_vars_for_becomes_such in b_read_write_info
1776
1777
1778 uses_an_identifier(Expr,Id) :- uses_an_identifier(Expr,Id,none,[]).
1779
1780 uses_an_identifier(identifier(Id),Id,_,_).
1781 uses_an_identifier(lazy_lookup_pred(Id),Id,_,_).
1782 uses_an_identifier(lazy_lookup_expr(Id),Id,_,_).
1783 uses_an_identifier(value(_),Id,b(_,_,Info),Ignored) :- Ignored \= [],
1784 ? member(was_identifier(Id),Info),
1785 member('$examine_value_was_identifier_info',Ignored),!.
1786
1787 % uses multiple ids and we also need to inspect subs (operation call arguments)
1788 indirectly_uses_identifiers(operation_call_in_expr(Operation,_),Ignored,IndirectIds) :-
1789 get_texpr_info(Operation,Info),
1790 (memberchk(reads(Vars),Info)
1791 -> (var(Vars) % can happen during initial computation of read_write info for recursive operation calls in expr
1792 -> add_message(bsyntaxtree,'Operation reads info not yet computed (probably recursive call): ',Operation,Info),
1793 fail % Assume this is a direct recursive call which adds no used ids,
1794 % case happens in test 1960 for recursive call to Fact; TODO: more robust solution or disallow recursion
1795 ; true)
1796 ; add_warning(bsyntaxtree,'Operation call contains no read infos:',Operation,Info),fail),
1797 ord_subtract(Vars,Ignored,IndirectIds),
1798 IndirectIds \= [].
1799 %indirectly_uses_identifiers(external_pred_call(FunName,_),Ignored,IndirectIds) :-
1800 % expects_state(FunName), TODO: check for which external functions/predicates we need to add ids
1801
1802
1803 % this is to convert untyped ids in operation call reads infos to typed ids
1804 add_typed_ids([]) --> [].
1805 add_typed_ids([Id|T]) --> {var_cst_type(Id,Type)},!,
1806 {create_texpr(identifier(Id),Type,[],TId)}, [TId], add_typed_ids(T).
1807 add_typed_ids([Id|T]) --> {debug_println(19,ignoring_used_id(Id))}, add_typed_ids(T).
1808
1809 :- use_module(bmachine,[bmachine_is_precompiled/0, b_is_variable/2,b_is_constant/2]).
1810 var_cst_type(Name,Type) :- bmachine_is_precompiled,!,
1811 (b_is_variable(Name,Type) ; b_is_constant(Name,Type)),!.
1812 var_cst_type(_,any). % TODO: provide a better solution; maybe only allow untyped find_identifier_uses ??
1813
1814 % -------------
1815
1816 find_typed_identifier_uses_l(TExprs,Ignored,Ids) :-
1817 check_atomic_ids(Ignored),
1818 list_to_ord_set(Ignored,SIgnored),
1819 find_typed_identifier_uses2_l(TExprs,SIgnored,Unsorted,[]),!,
1820 safe_sort(find_typed_identifier_uses,Unsorted,Ids),
1821 (preference(prob_safe_mode,true) -> check_typed_ids(Ids) ; true).
1822 find_typed_identifier_uses_l(TExprs,Ignored,Ids) :-
1823 add_internal_error('Call failed:',find_typed_identifier_uses_l(TExprs,Ignored,Ids)),
1824 fail.
1825
1826 check_typed_ids([]) :- !.
1827 check_typed_ids([b(identifier(ID),T,_)|Tail]) :- !, check_ids3(Tail,ID,T).
1828 check_typed_ids(Other) :- add_internal_error('Unexpected typed id list:',check_typed_ids(Other)).
1829
1830
1831 check_atomic_ids([]) :- !.
1832 check_atomic_ids([Id|_]) :- atomic(Id),!.
1833 check_atomic_ids(Other) :- add_internal_error('Expected atomic id list:',check_atomic_ids(Other)).
1834
1835
1836 check_ids3([],_,_) :- !.
1837 check_ids3([b(identifier(ID),T,_)|Tail],ID1,T1) :- !,
1838 (ID=ID1 -> add_internal_error('Identifier appears multiple times with types:',id(ID,T1,T)) ; true),
1839 check_ids3(Tail,ID,T).
1840 check_ids3(Other,ID1,T1) :- add_internal_error('Unexpected typed id list:',check_ids3(Other,ID1,T1)).
1841
1842
1843 update_used_ids(b(Pred,T,OInfo),UsedIds,b(Pred,T,[used_ids(UsedIds)|NInfo])) :-
1844 delete(OInfo,used_ids(_),NInfo).
1845
1846 % check if some pre-computed used ids are valid wrt find_typed_identifier_uses
1847 check_computed_used_ids(TExpr,CompUsedIds) :-
1848 find_identifier_uses(TExpr,[],RealUsedIds),
1849 (RealUsedIds=CompUsedIds -> print(ok(CompUsedIds)),nl
1850 ; add_error(range,'Unexpected used ids:',CompUsedIds,TExpr),
1851 format('Real: ~w~nComp: ~w~n',[RealUsedIds,CompUsedIds]),trace
1852 ).
1853
1854 %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
1855 % break predicate into components with disjunct identifiers
1856 % Pred: a predicate
1857 % Components: a list of terms component/2 where the first argument
1858 % is a predicate, the second is the set of used identifiers
1859 predicate_components(Pred,Res) :- predicate_components_in_scope(Pred,[],Res).
1860 predicate_components_in_scope(Pred,LocalVars,Res) :-
1861 predicate_components_with_restriction(Pred,LocalVars,all,Res).
1862
1863 predicate_components_with_restriction(Pred,LocalVars,RestrictionList,Res) :-
1864 conjunction_to_list(Pred,Preds),
1865 l_predicate_identifiers(Preds,LocalVars,PredIds),
1866 (RestrictionList=all -> R=all ; list_to_ord_set(RestrictionList,R)),
1867 try_find_and_remove_equalities(PredIds,PredIds2),
1868 % print(find_components(R)),nl,nl,
1869 %%(member(pred(P,Ids,X),PredIds2), nl,print(pred(Ids,X)),nl,translate:print_bexpr(P),nl,fail ; true),
1870 find_components(PredIds2,R,Components),
1871 !,
1872 %maplist(print_component,Components),
1873 Components=Res.
1874 predicate_components_with_restriction(Pred,_,_,[component(Pred,[])]) :-
1875 add_internal_error('predicate_components failed: ',predicate_components_with_restriction(Pred,_,_,_)).
1876
1877 % print_component(component(Pred,Ids)) :- format('Component over ~w :~n',[Ids]), translate:print_bexpr(Pred),nl.
1878
1879 % get the list of used identifiers for each predicate
1880 l_predicate_identifiers([],_LocalVars,[]).
1881 l_predicate_identifiers([Pred|PRest],LocalVars,[pred(Pred,Ids,_Selected)|IRest]) :-
1882 predicate_identifiers_in_scope(Pred,LocalVars,Ids), % Do not ignore local variables; used instead of enumerate set elements
1883 l_predicate_identifiers(PRest,LocalVars,IRest).
1884
1885
1886 try_find_and_remove_equalities(PredAndIds,PredAndIds2) :-
1887 preferences:get_preference(partition_predicates_inline_equalities,true),
1888 \+ preferences:get_preference(use_solver_on_load,kodkod),
1889 ? find_and_remove_equalities(PredAndIds,RR),
1890 !, PredAndIds2=RR.
1891 try_find_and_remove_equalities(Ps,Ps).
1892
1893 :- use_module(debug,[debug_println/2]).
1894 % find and apply obvious equalities so that they do not interfere with partitioning into components
1895 % example: c = 1 & f: 1..c --> A & g: 1..c --> B
1896 % TO DO: preprocess and do one pass to detect potential equalities
1897 find_and_remove_equalities([],[]).
1898 find_and_remove_equalities(List,[pred(P,PIds,Sel)|FT]) :-
1899 ? select(pred(P,PIds,Sel),List,Rest),
1900 %PIds = [Id],
1901 identifier_equality(P,Id,Value),
1902 %(value_which_can_be_replaced(Value) -> true ; nl,print('Not replaced: '),translate:print_bexpr(Value),nl,fail),
1903 (get_texpr_id(Value,Id2)
1904 -> Id2 \= Id %,print(inline_id(Id,Id2)),nl
1905 % Note: this inlining does *not* help with partitioning; but does help ProB detect common predicates/expressions
1906 ; PIds=[Id],value_which_can_be_replaced(Value)),
1907 debug_println(9,replace_simple_equality(Id,PIds)),
1908 ? maplist(apply_to_pred(Id,Value),Rest,RT),
1909 !,
1910 ? find_and_remove_equalities(RT,FT).
1911 % TO DO: detect equalityes x = EXPR, where EXPR does not contain x and where x occurs in no other predicate
1912 % we can then annotate x as not to enumerate
1913 find_and_remove_equalities(R,R).
1914
1915 identifier_equality(b(equal(LHS,RHS),_,_),Id,EqTerm) :-
1916 (get_texpr_id(LHS,Id) -> EqTerm = RHS
1917 ; get_texpr_id(RHS,Id) -> EqTerm = LHS).
1918 % TO DO: should we detect other equalities?
1919
1920 value_which_can_be_replaced(b(E,T,_)) :- value_which_can_be_replaced2(E,T).
1921 %(value_which_can_be_replaced2(E,T) -> true ; print(not_val(E)),nl,fail).
1922 value_which_can_be_replaced2(value(_),_).
1923 value_which_can_be_replaced2(integer(_),_).
1924 %value_which_can_be_replaced2(identifier(I),global(G)) :- b_global_constant(G), id_not_used_anywhere(I).
1925 value_which_can_be_replaced2(integer_set(_),_).
1926 value_which_can_be_replaced2(unary_minus(A),_) :- value_which_can_be_replaced(A).
1927 value_which_can_be_replaced2(add(A,B),_) :- value_which_can_be_replaced(A), value_which_can_be_replaced(B).
1928 % we could compute the value
1929 value_which_can_be_replaced2(minus(A,B),_) :- value_which_can_be_replaced(A), value_which_can_be_replaced(B).
1930 value_which_can_be_replaced2(multiplication(A,B),_) :- value_which_can_be_replaced(A), value_which_can_be_replaced(B).
1931 value_which_can_be_replaced2(div(A,B),_) :-
1932 get_integer(B,IB), IB \= 0,
1933 value_which_can_be_replaced(A).
1934 value_which_can_be_replaced2(floored_div(A,B),T) :- value_which_can_be_replaced2(div(A,B),T).
1935 % should we add: with WD check: division, modulo, .... ? see also simple2 in b_ast_cleanup
1936 value_which_can_be_replaced2(max_int,_).
1937 value_which_can_be_replaced2(min_int,_).
1938 value_which_can_be_replaced2(float_set,_).
1939 value_which_can_be_replaced2(real(_),_).
1940 value_which_can_be_replaced2(real_set,_).
1941 value_which_can_be_replaced2(string(_),_).
1942 value_which_can_be_replaced2(string_set,_).
1943 value_which_can_be_replaced2(boolean_true,_).
1944 value_which_can_be_replaced2(boolean_false,_).
1945 value_which_can_be_replaced2(bool_set,_).
1946 value_which_can_be_replaced2(empty_set,_).
1947 value_which_can_be_replaced2(empty_sequence,_).
1948 value_which_can_be_replaced2(couple(A,B),_) :- value_which_can_be_replaced(A), value_which_can_be_replaced(B).
1949 value_which_can_be_replaced2(interval(A,B),_) :- value_which_can_be_replaced(A), value_which_can_be_replaced(B).
1950 value_which_can_be_replaced2(set_extension(L),_) :- maplist(value_which_can_be_replaced,L).
1951 value_which_can_be_replaced2(sequence_extension(L),_) :- maplist(value_which_can_be_replaced,L).
1952 value_which_can_be_replaced2(cartesian_product(A,B),_) :- % typing equations, like t_float = INTEGER*NATURAL1
1953 simple_value_set(A), simple_value_set(B).
1954 value_which_can_be_replaced2(pow_subset(A),_) :- simple_value_set(A).
1955 %value_which_can_be_replaced2(identifier(_),_). % TO DO: check that this is not the LHS identifier which we replace !!
1956 % identifiers can also be replaced: we check above that the only identifier in the predicate is the equality identifier
1957 % TO DO: enable this but then we need to fix replace_id_by_expr2 to updated the used_ids info ! + we can have scoping issues !?; see test 1358
1958
1959 % TO DO: also allow inlining of prj1/prj2 of simple_value_set:
1960 % not_val(comprehension_set([b(identifier(_zzzz_unary),integer,[generated(first)]),b(identifier(_zzzz_binary),integer,[generated(first)]),b(identifier(_lambda_result_),integer,[lambda_result])],b(equal(b(identifier(_lambda_result_),integer,[lambda_result]),b(identifier(_zzzz_unary),integer,[generated(first)])),pred,[prob_annotation(LAMBDA),lambda_result])))
1961 % not_val(comprehension_set([b(identifier(_zzzz_unary),integer,[generated(second)]),b(identifier(_zzzz_binary),integer,[generated(second)]),b(identifier(_lambda_result_),integer,[lambda_result])],b(equal(b(identifier(_lambda_result_),integer,[lambda_result]),b(identifier(_zzzz_binary),integer,[generated(second)])),pred,[prob_annotation(LAMBDA),lambda_result])))
1962
1963 % TO DO: maybe check if it is an infinite type which cannot be evaluated anyway
1964 simple_value_set(b(E,_,_)) :- simple_value_set2(E).
1965 %simple_value_set2(bool_set). % Warning: we could have a finite construct which gets evaluated multiple times
1966 simple_value_set2(string_set).
1967 simple_value_set2(integer_set(_)).
1968 simple_value_set2(float_set).
1969 simple_value_set2(real_set).
1970 simple_value_set2(cartesian_product(A,B)) :- simple_value_set(A), simple_value_set(B).
1971 simple_value_set2(pow_subset(A)) :- simple_value_set(A).
1972 % POW, records struct(_) set ?
1973
1974 % apply a substiution of ID/Expr on a pred(EXPR,VarList,X) term
1975 % Expr must either be a variable or contain no variables at all
1976 apply_to_pred(ID,Expr,pred(E1,PIds1,X),pred(E2,PIds3,X)) :-
1977 ? (select(ID,PIds1,PIds2)
1978 ? -> replace_id_by_expr(E1,ID,Expr,E2), %,print(applied(ID)),nl,translate:print_bexpr(E2),nl
1979 % TO DO: replace_id_by_expr does not seem to update used_ids info !! check_used_ids_info fails for test 1358 if we allow identifiers inside Expr
1980 (get_texpr_id(Expr,NewID)
1981 -> ord_add_element(PIds2,NewID,PIds3)
1982 ; PIds3 = PIds2)
1983 %, format('Apply ~w -> ~w : ',[ID,NewID]),translate:print_bexpr(E2),nl
1984 ; E1=E2,PIds1=PIds3).
1985
1986
1987 % project a predicate : keep only those Predicates that are directly or
1988 % indirectly relevant for Ids; FullIds are all identifiers used by ProjectedPredicate
1989 project_predicate_on_identifiers(Pred,Ids,ProjectedPredicate,FullIds, RestList) :-
1990 (debug_mode(on)
1991 -> print('project: '),print_bexpr(Pred),nl, print(' on : '), print(Ids),nl
1992 ; true),
1993 conjunction_to_list(Pred,Preds),
1994 l_predicate_identifiers(Preds,[],PredIds), % TO DO: allow LocalVariables to be passed
1995 % print(predids(PredIds)),nl,
1996 try_find_and_remove_equalities(PredIds,PredIds2),
1997 extract_all_predicates(Ids,all,Ids,PredIds2,ProjectedPredicates, RestList,FullIds),
1998 conjunct_predicates(ProjectedPredicates,ProjectedPredicate),
1999 (debug_mode(on)
2000 -> print('*result: '),print_bexpr(ProjectedPredicate),nl,
2001 print(' on : '), print(FullIds),nl
2002 ; true).
2003
2004 %print_preds([]).
2005 %print_preds([pred(P,_IDs,_)|T]) :- translate:print_bexpr(P), nl, print(' '), print_preds(T).
2006
2007 :- use_module(b_global_sets,[b_get_global_constants/1, b_get_enumerated_set_constants/1,
2008 b_get_global_sets/1, exclude_global_identifiers/2, exclude_global_identifiers/3]).
2009 predicate_identifiers(Pred,Ids) :- predicate_identifiers_in_scope(Pred,[],Ids).
2010 predicate_identifiers_in_scope(Pred,LocalVariables,Ids) :-
2011 %get_global_identifiers(IS),
2012 list_to_ord_set(LocalVariables,LV),
2013 %ord_subtract(IS,LV,Ignore2), % Do not ignore any local variable; it will be used instead of enumerate set element
2014 find_identifier_uses_if_necessary(Pred,[],Ids1), % Ignore enumerated set names
2015 exclude_global_identifiers(Ids1,LV,Ids2),
2016 list_to_ord_set(Ids2,Ids).
2017
2018 % see also b_global_constant_or_set_identifier and exclude_global_identifiers
2019 get_global_identifiers(IDs) :- get_global_identifiers(IDs,all).
2020 % get global set and constant identifiers which you usually want to exclude for find_identifier_uses
2021 get_global_identifiers(IDs,Option) :-
2022 (Option=ignore_promoted_constants
2023 % do not include those constants that have been automatically promoted as enumerated set elements
2024 -> b_get_enumerated_set_constants(EnumeratedSetCsts)
2025 ; b_get_global_constants(EnumeratedSetCsts)
2026 ),
2027 % b_global_sets:b_get_global_enumerated_sets(GSets), % is there a reason to exclude deferred sets ??; cardinality inference,... are all done before partitioning ?
2028 b_get_global_sets(GSets),
2029 append(GSets,EnumeratedSetCsts,GE),
2030 list_to_ord_set(GE,IDs).
2031
2032 % find_components(ListOf_pred, Restrict, Out:ListOfComponents)
2033 % role of Restrict: all if we do normal partition or List of VariableIDs on which we restrict our attention to (for Existential quantifier construction)
2034 find_components([],_,[]).
2035 find_components([pred(P,PIds,true)|PRest],Restrict,[component(Pred,Ids)|CRest]) :-
2036 % find all predicates which are using identifiers occuring in PIds
2037 % (and additionally those which use common identifiers )
2038 ord_restrict(Restrict,PIds,InterIDs),
2039 %format('Treating predicate with ids ~w; restr. intersect = ~w~n',[PIds,InterIDs]),
2040 ( InterIDs =[] ->
2041 % we simply copy this predicate into a single component; not with the scope of Restricted IDs
2042 % print(skip(PIds,P)),nl, %
2043 Pred=P, Ids=PIds, PRest=Rest
2044 ;
2045 extract_all_predicates(InterIDs,Restrict,PIds,PRest,Preds,Rest,Ids),
2046 %length([P|Preds],Len), format('Detected component with ~w conjuncts over ~w~n',[Len,Ids]),
2047 conjunct_predicates_with_pos_info([P|Preds],Pred)
2048 ),
2049 find_components(Rest,Restrict,CRest).
2050 extract_all_predicates([],_,_,Preds,Found,Rest,[]) :- !, % selecting done at end: keep same order of conjuncts
2051 select_predicates(Preds,Found,Rest).
2052 extract_all_predicates(Ids,Restrict,OldIds,Preds,Found,Rest,ResultIds) :-
2053 % search for all predicates that directly use one of the
2054 % identifiers in "Ids"
2055 select_all_using_preds(Preds,Ids,FoundIds),
2056 ord_subtract(FoundIds,OldIds,NewIds),
2057 ord_restrict(Restrict,NewIds,NewIdsToExtract),
2058 ord_union(OldIds,FoundIds,OldIds2),
2059 % now recursively do this which the new identifiers that we have found
2060 extract_all_predicates(NewIdsToExtract,Restrict,OldIds2,Preds,Found,Rest,RestIds),
2061 ord_union([Ids,NewIds,RestIds],ResultIds).
2062
2063 % mark all predicates which intersect with ComponentIds and compute new ids to be added to the component
2064 select_all_using_preds([],_,[]).
2065 select_all_using_preds([pred(_P,PIds,Selected)|PRest],ComponentIds,NewFoundIds) :-
2066 ( (Selected==true ; ord_disjoint(PIds,ComponentIds)) ->
2067 NewFoundIds1 = []
2068 ; % we select the predicate for the component
2069 ord_subtract(PIds,ComponentIds,NewFoundIds1),
2070 Selected=true
2071 ),
2072 select_all_using_preds(PRest,ComponentIds,NewFoundIds2),
2073 ord_union(NewFoundIds1,NewFoundIds2,NewFoundIds).
2074
2075 % ord_intersection with special case for all term
2076 ord_restrict(all,Ids,Res) :- !, Res=Ids.
2077 ord_restrict(Restrict,Ids,Res) :- ord_intersection(Ids,Restrict,Res).
2078
2079 select_predicates(Predicates,FoundPreds,OtherPreds) :-
2080 split_list(is_selected_predicate,Predicates,FoundPredIds,OtherPreds),
2081 maplist(extract_found_predicate,FoundPredIds,FoundPreds).
2082 is_selected_predicate(pred(_P,_PIds,Selected)) :- ground(Selected).
2083 extract_found_predicate(pred(P,_PIds,_Selected),P).
2084
2085 %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
2086 % replace (simultaneously) multiple identifiers by expressions
2087 % this could be used to replace the predicate replace_id_by_expr by mapping everything in a
2088 % singleton list. however, that would involve list operations instead of unifications
2089 parse_pred(Codes,TExpr) :- %format('Parsing ~s~n',[Codes]),
2090 bmachine:b_parse_machine_predicate_from_codes_open(no_quantifier,Codes,[],[],TExpr).
2091 parse_expr(Codes,TExpr) :- bmachine:b_parse_machine_expression_from_codes(Codes,[],TExpr,_Type,true,_Error).
2092 test_result(1,b(equal(b(comprehension_set([b(identifier(__FRESH____),integer,_)],
2093 b(greater(b(identifier(__FRESH____2),integer,_),b(identifier(x),integer,_)),pred,_)),set(integer),_),
2094 b(empty_set,set(integer),_)),pred,_)).
2095
2096 :- assert_must_succeed((bsyntaxtree:parse_pred("{x|x:INTEGER & x>y}={}",T1), replace_ids_by_exprs(T1,[],[],T1))).
2097 :- assert_must_succeed((bsyntaxtree:parse_pred("{x|x:INTEGER & x>y}={}",T1), bsyntaxtree:parse_expr("100",T2),
2098 replace_ids_by_exprs(T1,[y],[T2],R),bsyntaxtree:parse_pred("{x|x>100}={}",T3),same_texpr(R,T3) )).
2099 :- assert_must_succeed((bsyntaxtree:parse_pred("{x|x:INTEGER & x>y}={}",T1),
2100 replace_ids_by_exprs(T1,[y],[b(identifier(x),integer,[])],R),
2101 bsyntaxtree:test_result(1,R),bsyntaxtree:parse_pred("{x|x:INTEGER & x>x}={}",T3),\+ same_texpr(R,T3) )).
2102 :- assert_must_succeed((bsyntaxtree:parse_pred("{x,y|x:INTEGER & y:INTEGER & x>v & y>w}={}",T1),
2103 replace_ids_by_exprs(T1,[v,w],[b(identifier(w),integer,[]),b(identifier(v),integer,[])],R),
2104 bsyntaxtree:parse_pred("{x,y|x:INTEGER & y:INTEGER & x>w & y>v}={}",T3), same_texpr(R,T3) )).
2105 :- assert_must_succeed((gensym:reset_gensym, bsyntaxtree:parse_pred("{x,y|x:INTEGER & y:INTEGER & x>v & y>w}={}",T1),
2106 replace_ids_by_exprs(T1,[v,w],[b(identifier(w),integer,[]),b(identifier(x),integer,[])],R),
2107 translate:translate_bexpression(R,TR),
2108 TR = '{`__FRESH____1`,y|`__FRESH____1` > w & y > x} = {}')). %'{__FRESH____1,y|(__FRESH____1 : INTEGER & y : INTEGER) & (__FRESH____1 > w & y > x)} = {}' )).
2109
2110 replace_ids_by_exprs(TExpr,[TId],[Inserted],Replaced) :- !, % better, more robust and efficient version
2111 check_ids([TId],[Id]),
2112 ? replace_id_by_expr(TExpr,Id,Inserted,Replaced).
2113 replace_ids_by_exprs(TExpr,[],[],Replaced) :- !, Replaced=TExpr. % Nothing to do
2114 replace_ids_by_exprs(TExpr,Ids,Exprs,Replaced) :-
2115 check_ids(Ids,Ids2), % convert to atomic identifiers
2116 find_identifier_uses_l(Exprs,[],ExprsUsedIds),
2117 sort(ExprsUsedIds,SExprsUsedIds),
2118 generate_rename_list(Ids2,Exprs,RenameList),
2119 %print(replace(RenameList,SExprsUsedIds)),nl,
2120 replace_ids_by_exprs2(RenameList,SExprsUsedIds,TExpr,Replaced,_). %, nl,print(done),nl.
2121 % a version of replace_ids_by_exprs2 for maplist:
2122 %replace_ids_by_exprs1(RenameList,SExprsUsedIds,TExpr,Replaced) :-
2123 % replace_ids_by_exprs2(RenameList,SExprsUsedIds,TExpr,Replaced,_). %, print('Rep: '), translate:print_bexpr(Replaced),nl.
2124
2125 generate_rename_list([],[],[]).
2126 generate_rename_list([ID1|T],[Expr1|TE],[rename(ID1,Expr1)|RT]) :- generate_rename_list(T,TE,RT).
2127
2128 check_ids([],[]).
2129 check_ids([H|T],[ID|IT]) :- (atomic(H) -> ID=H ; def_get_texpr_id(H,ID)), check_ids(T,IT).
2130 replace_ids_by_exprs2(RenameList,ExprsUsedIds,TExpr,Replaced,WDC) :-
2131 remove_bt(TExpr,Expr,NewExpr,TNewExpr),
2132 ? ( Expr = identifier(Id), member(rename(Id,Inserted),RenameList) ->
2133 Replaced = Inserted,
2134 get_texpr_info(Inserted,Infos),
2135 (memberchk(contains_wd_condition,Infos)
2136 -> WDC = true ; WDC = false) % WDC = true means we have added a wd-condition where previously there was none
2137 ; contains_no_ids(Expr) -> Replaced=TExpr, WDC=false
2138 ;
2139 syntaxtransformation_det(Expr,Subs1,Names,NSubs,NewExpr),
2140 find_variable_clashes(Names,ExprsUsedIds,RenameNames), % check for variable caputure
2141 (RenameNames = []
2142 -> Subs = Subs1 % no variable capture occured
2143 ; %format('*** VARIABLE CAPTURE : ~w~n~n',[RenameNames]),
2144 rename_bt_l(Subs1,RenameNames,Subs) % replace affected names by fresh ids in sub arguments (will also change list of quantified variables itself)
2145 ),
2146 %l_replace_ids_by_exprs2(QSubs,RenameList,ExprsUsedIds,NQSubs,WDC1), % QSubs are like RHS of let expression, where Names are not in scope
2147 remove_hidden_names(Names,RenameList,UpdatedRenameList),
2148 ( UpdatedRenameList = [] -> % all Ids are now hidden for the inner expressions
2149 NSubs=Subs, WDC=false
2150 ;
2151 l_replace_ids_by_exprs2(Subs,UpdatedRenameList,ExprsUsedIds,NSubs,WDC)
2152 ),
2153 TNewExpr = b(E1,T1,Info1),
2154 rename_update_used_ids_info(RenameList,Info1,Info2),
2155 add_wd_if_needed(WDC,b(E1,T1,Info2),Replaced)
2156 ).
2157
2158 contains_no_ids(integer(_)).
2159 contains_no_ids(string(_)).
2160 contains_no_ids(value(_)).
2161
2162
2163 % check if we have to rename any quantified variable to avoid variable capture of RHS of renamings
2164 % example, suppose we rename x/y+1 and we enter {y|y>x} we have to generate {fresh|fresh>y+1} and *not* {y|y>y+1}
2165 find_variable_clashes([],_,[]).
2166 find_variable_clashes([Name|Names],ExprsUsedIds,[rename(ID,FRESHID)|Renaming] ) :-
2167 def_get_texpr_id(Name,ID),
2168 ord_member(ID,ExprsUsedIds), % the quantified name is also introduced by the renaming
2169 !,
2170 gensym('__FRESH__',FRESHID),
2171 find_variable_clashes(Names,ExprsUsedIds,Renaming).
2172 find_variable_clashes([_|Names],ExprsUsedIds,Renaming) :-
2173 find_variable_clashes(Names,ExprsUsedIds,Renaming).
2174
2175
2176 l_replace_ids_by_exprs2([],_,_,[],false).
2177 l_replace_ids_by_exprs2([H|T],UpdatedRenameList,ExprsUsedIds,[IH|IT],WDC) :-
2178 replace_ids_by_exprs2(UpdatedRenameList,ExprsUsedIds,H,IH,WDC1),
2179 l_replace_ids_by_exprs2(T,UpdatedRenameList,ExprsUsedIds,IT,WDC2),
2180 and_wdc(WDC1,WDC2,WDC).
2181
2182 % remove any identifiers that are now "invisible" because they are masked by quantified names
2183 % e.g., when we enter #x.(P) then a renaming of x will be "hidden" inside P
2184 remove_hidden_names([],RenameList,RenameList).
2185 remove_hidden_names([Name|Names],RenameList,NewRenameList) :-
2186 def_get_texpr_id(Name,ID),
2187 delete(RenameList,rename(ID,_),RenameList1),
2188 !, % only one rename should exist
2189 %print(del(ID,RenameList1)),nl,
2190 remove_hidden_names(Names,RenameList1,NewRenameList).
2191
2192 find_rhs_ids(rename(Id,TExpr),rename_ids(Id,InsUsedIds)) :- find_identifier_uses(TExpr,[],InsUsedIds).
2193
2194 % apply a rename list to the used_ids,... information fields
2195 % this is more tricky than applying a single identifier, as we first have to deleted all ids
2196 % and remember which ones were deleted, and only then insert the corresponding ids
2197 % e.g., we could have a RenameList = [rename(p,q),rename(q,p)] ; see test 1776 M1_Internal_v3.mch
2198 rename_update_used_ids_info(RenameList,IIn,IOut) :-
2199 l_find_rhs_ids(RenameList,RenameList2),
2200 %maplist(apply_rename_list(RenameList2),IIn,IOut).
2201 l_apply_rename_list(IIn,RenameList2,IOut).
2202
2203 l_find_rhs_ids([],[]).
2204 l_find_rhs_ids([R1|T],[NR1|NTR]) :-
2205 find_rhs_ids(R1,NR1),
2206 l_find_rhs_ids(T,NTR).
2207
2208 l_apply_rename_list([],_,[]).
2209 l_apply_rename_list([Info1|T],RenameList2,[NewInfo1|NTI]) :-
2210 apply_rename_list(RenameList2,Info1,NewInfo1),
2211 l_apply_rename_list(T,RenameList2,NTI).
2212
2213 apply_rename_list(RenameList,I,NI) :-
2214 apply_rename_list2(I,RenameList,NI).
2215 apply_rename_list2(used_ids(IDS),RenameList,used_ids(NewIDS)) :- !, apply_rename_list_to_ids(RenameList,IDS,[],NewIDS).
2216 apply_rename_list2(reads(IDS),RenameList,reads(NewIDS)) :- !, apply_rename_list_to_ids(RenameList,IDS,[],NewIDS).
2217 apply_rename_list2(modifies(IDS),RenameList,modifies(NewIDS)) :- !, apply_rename_list_to_ids(RenameList,IDS,[],NewIDS).
2218 apply_rename_list2(Info,_,Info).
2219
2220 % apply a rename list to a sorted list of ids
2221 apply_rename_list_to_ids([],Acc,ToInsert,Res) :- ord_union(Acc,ToInsert,Res).
2222 apply_rename_list_to_ids([rename_ids(Id,NewIds)|T],Acc,ToInsert,Res) :-
2223 (ord_delete_existing_element(Acc,Id,Acc2) % the Id occurs and is deleted
2224 -> ord_union(NewIds,ToInsert,ToInsert2),
2225 apply_rename_list_to_ids(T,Acc2,ToInsert2,Res)
2226 ; apply_rename_list_to_ids(T,Acc,ToInsert,Res)).
2227
2228 ord_delete_existing_element(List,El,ResList) :- % ord_del_element also succeeds if El is not in the list !
2229 ord_intersection([El],List,[El],ResList).
2230 % -----------------------
2231 % remove an Identifier from used_ids Info field if it exists
2232 remove_used_id_from_info(I,ID_to_remove,NI) :-
2233 update_used_ids_info(I,ID_to_remove,[],NI).
2234
2235 remove_used_ids_from_info([],I,I).
2236 remove_used_ids_from_info([ID_to_remove|T],I,NI) :- remove_used_id_from_info(I,ID_to_remove,I2),
2237 remove_used_ids_from_info(T,I2,NI).
2238
2239 % remove a single Identifier from used_ids Info field if it exists and insert sorted list of ids instead
2240 % a simpler version of rename_update_used_ids_info for a single identifier
2241 update_used_ids_info([],_,_,[]).
2242 update_used_ids_info([InfoField|T],ID_to_remove,IDsInserted,[NewInfoField|NT]) :-
2243 (update_id_from_info_field(ID_to_remove,IDsInserted,InfoField,R)
2244 -> NewInfoField=R
2245 ; NewInfoField=InfoField),
2246 update_used_ids_info(T,ID_to_remove,IDsInserted,NT).
2247
2248 update_id_from_info_field(ID_to_remove,IDsInserted,I,NI) :-
2249 update_id_from_info_field2(I,ID_to_remove,IDsInserted,NI).
2250 update_id_from_info_field2(used_ids(IDS),ID,IDsInserted,used_ids(NewIDS)) :- update_id(IDS,ID,IDsInserted,NewIDS).
2251 update_id_from_info_field2(reads(IDS),ID,IDsInserted,reads(NewIDS)) :- update_id(IDS,ID,IDsInserted,NewIDS).
2252 update_id_from_info_field2(modifies(IDS),ID,IDsInserted,modifies(NewIDS)) :- update_id(IDS,ID,IDsInserted,NewIDS).
2253
2254 update_id(IDS,ID_to_remove,IDsInserted,NewIDS) :-
2255 ord_delete_existing_element(IDS,ID_to_remove,IDS2), % the Id occurs and is deleted
2256 ord_union(IDsInserted,IDS2,NewIDS).
2257 %if ord_del_element fails we do not add IDsInserted: we assume the used_ids info is correct and ID_to_remove does not occur !
2258 % We could use this info to avoid traversing subtree !
2259 % print(projecting_away_unknown_id(ID_to_remove,IDS)),nl,
2260
2261 %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
2262
2263 :- assert_must_succeed((gensym:reset_gensym, bsyntaxtree:exists_ast(A), replace_id_by_expr(A,y,b(identifier(x),integer,[]),RA),translate:translate_bexpression(RA,TR),
2264 TR = 'r = {`__FRESH____1`|`__FRESH____1` : 1 .. x & `__FRESH____1` mod 2 = 1}' )).
2265 :- assert_must_succeed((bsyntaxtree:parse_pred("{x|x:INTEGER & x>y}={}",T1),
2266 replace_id_by_expr(T1,y,b(identifier(x),integer,[]),R),
2267 bsyntaxtree:test_result(1,R),bsyntaxtree:parse_pred("{x|x:INTEGER & x>x}={}",T3),
2268 \+ same_texpr(R,T3) )).
2269 :- assert_must_succeed((bsyntaxtree:parse_pred("{x|x:INTEGER & x>y}={}",T1), bsyntaxtree:parse_expr("100",T2),
2270 replace_id_by_expr(T1,y,T2,R),bsyntaxtree:parse_pred("{x|x>100}={}",T3),same_texpr(R,T3) )).
2271
2272 % replace an identifier Id by an expression Inserted
2273 replace_id_by_expr(TExpr,Id,Inserted,Replaced) :-
2274 ? replace_id_by_expr_with_count(TExpr,Id,Inserted,Replaced,_).
2275
2276 replace_id_by_expr_with_count(TExpr,Id,Inserted,Replaced,NrReplacements) :- \+ atomic(Id),!,
2277 add_internal_error('Id not atomic: ',replace_id_by_expr(TExpr,Id,Inserted,Replaced)),
2278 Replaced = TExpr, NrReplacements=0.
2279 replace_id_by_expr_with_count(TExpr,Id,Inserted,Replaced,NrReplacements) :-
2280 %find_all_relevant_quantified_vars(Id,TExpr,QVars),
2281 find_identifier_uses(Inserted,[],SInsUsedIds), % SInsUsedIds is sorted
2282 ? replace_id_by_expr2(Id,Inserted,SInsUsedIds,TExpr,Replaced,_WDC,0,NrReplacements).
2283
2284 replace_id_by_expr2(Id,Inserted,InsUsedIds,TExpr,Replaced,WDC,InR,OutR) :-
2285 remove_bt(TExpr,Expr,NewExpr,TNewExpr),
2286 ( Expr = identifier(Id) -> % TODO: count number of replacements
2287 Replaced = Inserted,
2288 OutR is InR+1,
2289 get_texpr_info(Inserted,Infos),
2290 (memberchk(contains_wd_condition,Infos)
2291 -> WDC = true ; WDC = false) % WDC = true means we have added a wd-condition where previously there was none
2292 ; contains_no_ids(Expr) -> Replaced=TExpr, WDC=false, OutR=InR
2293 ;
2294 ? syntaxtransformation_det(Expr,Subs,Names,NSubs,NewExpr),
2295 get_texpr_id(TId,Id),
2296 ( memberchk(TId,Names) -> % the Id is now hidden for the inner expressions
2297 NSubs=Subs, WDC=false, OutR = InR
2298 ; (InsUsedIds \= [],
2299 get_texpr_ids(Names,Ns),sort(Ns,SNs),
2300 ord_intersection(SNs,InsUsedIds,Captured),
2301 Captured \= [] %, print(inter(SNs,InsUsedIds,Captured)),nl
2302 )
2303 % The Names introduced clash with variables used in the Inserted expression
2304 -> findall(rename(X,FRESHID),(member(X,Captured),gensym:gensym('__FRESH__',FRESHID)),RenameList),
2305 %print(rename(RenameList)),nl,
2306 rename_bt_l(Subs,RenameList,RenSubs),
2307 l_replace_id_by_expr2(RenSubs,Id,Inserted,InsUsedIds,NSubs,WDC,InR,OutR)
2308 ;
2309 ? l_replace_id_by_expr2(Subs,Id,Inserted,InsUsedIds,NSubs,WDC,InR,OutR)
2310 ),
2311 TNewExpr = b(E1,T1,Info1),
2312 update_used_ids_info(Info1,Id,InsUsedIds,Info2),
2313 %(E1 = exists(P,_) -> print(exists(P,Id,Info1,Info2)),nl ; true),
2314 add_wd_if_needed(WDC,b(E1,T1,Info2),Replaced)
2315 ).
2316
2317 l_replace_id_by_expr2([],_,_,_,[],false,R,R).
2318 l_replace_id_by_expr2([H|T],Id,Inserted,InsUsedIds,[IH|IT],WDC,InR,OutR) :-
2319 ? replace_id_by_expr2(Id,Inserted,InsUsedIds,H,IH,WDC1,InR,InR2),
2320 ? l_replace_id_by_expr2(T,Id,Inserted,InsUsedIds,IT,WDC2,InR2,OutR),
2321 and_wdc(WDC1,WDC2,WDC).
2322
2323 % conjunct wd condition added flag
2324 and_wdc(true,_,R) :- !,R=true.
2325 and_wdc(_,true,R) :- !, R=true.
2326 and_wdc(_,_,false).
2327
2328 % add contains_wd_condition if a change occured during replacement of id by expression
2329 add_wd_if_needed(true,b(E,T,Infos),Replaced) :-
2330 nonmember(contains_wd_condition,Infos),
2331 !,
2332 Replaced = b(E,T,[contains_wd_condition|Infos]).
2333 add_wd_if_needed(_,T,T).
2334
2335
2336
2337 %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
2338
2339
2340 % syntaxtransformation_fixed/7 is the same as syntaxtransformation/5 with the exception
2341 % that we distinguish between subexpressions that have the newly introduced identifiers (Names)
2342 % in scope (OSubs) and those who don't (OExprs). The only expressions where the latter case is relevant
2343 % are let_expression and let_predicate.
2344 % TODO: This is a quick'n dirty fix for only some cases.
2345 % NO LONGER REQUIRED: let_expression and let_predicate now obey another semantic, not the Z semantics anymore
2346 %syntaxtransformation_fixed(OExpr,OExprs,OSubs,Names,NExprs,NSubs,NExpr) :-
2347 %syntaxtransformation_fixed(Expr,[],Subs,Names,[],NSubs,NExpr) :-
2348 % syntaxtransformation_det(Expr,Subs,Names,NSubs,NExpr).
2349
2350
2351 %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
2352 % rename identifier
2353
2354 % r = {x|x : 1..y & x mod 2 = 1}
2355 exists_ast(AST) :- AST =
2356 b(equal(b(identifier(r),set(integer),[nodeid(none)]),
2357 b(comprehension_set([b(identifier(x),integer,[nodeid(none)])],
2358 b(conjunct(b(member(b(identifier(x),integer,[nodeid(none)]),
2359 b(interval(b(integer(1),integer,[nodeid(none)]),b(identifier(y),integer,[nodeid(none)])),
2360 set(integer),[nodeid(none)])),pred,[nodeid(none)]),
2361 b(equal(b(modulo(b(identifier(x),integer,[nodeid(none)]),
2362 b(integer(2),integer,[nodeid(none)])),integer,[contains_wd_condition,nodeid(none)]),
2363 b(integer(1),integer,[nodeid(none)])),pred,
2364 [contains_wd_condition,nodeid(none)])),pred,[contains_wd_condition,nodeid(none)])),
2365 set(integer),[contains_wd_condition,nodeid(none)])),
2366 pred,[contains_wd_condition,nodeid(none)]).
2367
2368 :- assert_must_succeed((bsyntaxtree:exists_ast(A), rename_bt(A,[rename(x,xx)],RA), RA==A )).
2369 :- assert_must_succeed((bsyntaxtree:exists_ast(A), rename_bt(A,[rename(r,v)],RA),
2370 translate:translate_bexpression(RA,TR), TR='v = {x|x : 1 .. y & x mod 2 = 1}' )).
2371 :- assert_must_succeed((gensym:reset_gensym, bsyntaxtree:exists_ast(A), rename_bt(A,[rename(y,x)],RA), RA \= A,
2372 translate:translate_bexpression(RA,TR),
2373 TR = 'r = {`__FRESH____1`|`__FRESH____1` : 1 .. x & `__FRESH____1` mod 2 = 1}' )).
2374
2375 % a simplified version of replace_ids_by_exprs, which assumes target of renamings are variables
2376 rename_bt(Expr,[],Res) :- !,Res=Expr.
2377 rename_bt(OExpr,Renamings,NExpr) :-
2378 create_texpr(Old,Type,OInfo,OExpr),
2379 create_texpr(New,Type,NInfo,NExpr),
2380 ? rename_in_infos(OInfo,Renamings,NInfo),
2381 ? rename_bt2(Old,Renamings,New).
2382 rename_bt2(identifier(Old),Renamings,identifier(New)) :-
2383 !, rename_id(Old,Renamings,New).
2384 rename_bt2(lazy_lookup_expr(Old),Renamings,lazy_lookup_expr(New)) :-
2385 !, rename_id(Old,Renamings,New).
2386 rename_bt2(lazy_lookup_pred(Old),Renamings,lazy_lookup_pred(New)) :-
2387 !, rename_id(Old,Renamings,New).
2388 rename_bt2(OExpr,Renamings,NExpr) :-
2389 ? syntaxtransformation_for_renaming(OExpr,Subs,TNames,NSubs,NExpr),
2390 get_texpr_exprs(TNames,Names),
2391 remove_renamings(Names,Renamings,NRenamings),
2392 ? rename_bt_l(Subs,NRenamings,NSubs).
2393 rename_bt_l([],_,[]).
2394 rename_bt_l([Old|ORest],Renamings,[New|NRest]) :-
2395 ? rename_bt(Old,Renamings,New),
2396 ? rename_bt_l(ORest,Renamings,NRest).
2397
2398 % syntaxtransformation rule for operation_call_in_expr does not show Id field in sub expressions
2399 % (to avoid issues with find_identifier_uses, see below)
2400 % so here we explicitly also rename the operation name if required, relevant for bmachine_construction, test 2504
2401 % TODO: avoid this special case and fix find_identifier_uses instead
2402 syntaxtransformation_for_renaming(operation_call_in_expr(ID,Subs1),Subs,TNames,NSubs,NExpr) :- !,
2403 NExpr = operation_call_in_expr(NID,NSubs1),
2404 Subs = [ID|Subs1],
2405 NSubs = [NID|NSubs1], TNames = [].
2406 syntaxtransformation_for_renaming(OExpr,Subs,TNames,NSubs,NExpr) :-
2407 ? syntaxtransformation(OExpr,Subs,TNames,NSubs,NExpr).
2408
2409 remove_renamings([],Renamings,Renamings).
2410 remove_renamings([identifier(Name)|Rest],Old,New) :-
2411 ? ( select(rename(Name,_),Old,Inter1) -> true % Name no longer visible to renaming
2412 ; Old = Inter1),
2413 ? (member(rename(_OldName,Name),Inter1) ->
2414 % rename the local identifier Name, to avoid clash with the outer Name
2415 % (in case _OldName is used inside)
2416 gensym('__FRESH__',FRESHID),
2417 %print(variable_capture_in_rename(Name,from(OldName),FRESHID)),nl,
2418 Inter2 = [rename(Name,FRESHID)|Inter1]
2419 ; Inter2 = Inter1),
2420 remove_renamings(Rest,Inter2,New).
2421
2422 rename_in_infos(Old,Renamings,New) :-
2423 ( has_info_to_rename(Old) ->
2424 ? maplist(rename_in_infos2(Renamings),Old,New)
2425 ;
2426 Old = New).
2427 rename_in_infos2(Renamings,OInfo,NInfo) :-
2428 ( infos_to_rename(OInfo,OIds,SortedNIds,NInfo) ->
2429 ? rename_ids(OIds,Renamings,NIds),
2430 sort(NIds,SortedNIds)
2431 ;
2432 OInfo = NInfo).
2433
2434 rename_ids([],_,[]).
2435 rename_ids([OId|Orest],Renamings,[NId|Nrest]) :-
2436 rename_id(OId,Renamings,NId),
2437 rename_ids(Orest,Renamings,Nrest).
2438 rename_id(Old,Renamings,New) :-
2439 ( memberchk(rename(Old,New),Renamings) -> true % we could use ord_member if we sort !
2440 ; Old=New).
2441
2442 has_info_to_rename(Infos) :-
2443 ? member(I,Infos),infos_to_rename(I,_,_,_),!.
2444
2445 infos_to_rename(modifies(O),O,N,modifies(N)).
2446 infos_to_rename(reads(O),O,N,reads(N)).
2447 infos_to_rename(non_det_modifies(O),O,N,non_det_modifies(N)).
2448 infos_to_rename(modifies_locals(O),O,N,modifies_locals(N)).
2449 infos_to_rename(reads_locals(O),O,N,reads_locals(N)).
2450 infos_to_rename(used_ids(O),O,N,used_ids(N)).
2451 %infos_to_rename(lambda_result(O),[O],[N],lambda_result(N)). % whould we no longer assume that we have lambda result, as predicate has possibly changed!?
2452
2453
2454 %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
2455 % remove type information for transformations
2456
2457 remove_bt(b(Expr,Type,Infos),Expr,NExpr,b(NExpr,Type,Infos)).
2458
2459 remove_bt_and_used_ids(b(OldExpr,T,Infos),OldExpr,NewExpr,b(NewExpr,T,NewInfos)) :-
2460 delete(Infos,used_ids(_),NewInfos). % invalidate used_ids info
2461
2462 %remove_bt_l([],[],[],[]).
2463 %remove_bt_l([OT|OTRest],[O|ORest],[N|NRest],[NT|NTRest]) :-
2464 % remove_bt(OT,O,N,NT),
2465 % remove_bt_l(OTRest,ORest,NRest,NTRest).
2466
2467 %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
2468 % traversations
2469 % Takes a predicate or expression or substitution and extracts:
2470 % the expression itself Expr, its type Type, the syntaxnode information Infos
2471 % + the subexpressions as a list Subs and the local identifiers declared
2472 syntaxtraversion(b(Expr,Type,Infos),Expr,Type,Infos,Subs,Names) :- !,
2473 safe_syntaxelement(Expr,Subs,Names,_,_).
2474 syntaxtraversion(IExpr,Expr,Type,Infos,Subs,Names) :-
2475 add_internal_error('Not properly wrapped', syntaxtraversion(IExpr,Expr,Type,Infos,Subs,Names)),
2476 fail.
2477
2478
2479 map_over_full_bexpr_no_fail(P,BExpr) :-
2480 syntaxtraversion(BExpr,Expr,_,_,Subs,_TNames),
2481 call(P,Expr), % the predicate should not fail
2482 (Subs=[] -> true ; maplist(map_over_full_bexpr_no_fail(P),Subs)).
2483
2484 map_over_bexpr(P,BExpr) :-
2485 syntaxtraversion(BExpr,Expr,_,_,Subs,_TNames),
2486 ? (call(P,Expr) % should probably fail so that by backtrack we recurse
2487 ;
2488 ? member(Sub,Subs), map_over_bexpr(P,Sub)
2489 ).
2490 % same as above but gets typed expressions:
2491 map_over_typed_bexpr(P,BExpr) :-
2492 syntaxtraversion(BExpr,_Expr,_,_,Subs,_TNames),
2493 ? (call(P,BExpr)
2494 ;
2495 ? member(Sub,Subs), map_over_typed_bexpr(P,Sub)
2496 ).
2497 % same as above but returns value:
2498 map_over_typed_bexpr(P,BExpr,Result) :-
2499 syntaxtraversion(BExpr,_Expr,_,_,Subs,_TNames),
2500 ? (call(P,BExpr,Result)
2501 ;
2502 ? member(Sub,Subs), map_over_typed_bexpr(P,Sub,Result)
2503 ).
2504 % this one gets TNames (locally introduced variables as parameter)
2505 map_over_typed_bexpr_with_names(P,BExpr) :-
2506 syntaxtraversion(BExpr,_Expr,_,_,Subs,TNames),
2507 (call(P,BExpr,TNames)
2508 ;
2509 ? member(Sub,Subs), map_over_typed_bexpr_with_names(P,Sub)
2510 ).
2511
2512 % same as map_over_expr but provides an accumulator passed top-down to children; needs to be used by failure driven loop
2513
2514 map_over_bexpr_top_down_acc(P,BExpr,TDAcc) :-
2515 syntaxtraversion(BExpr,Expr,_,_,Subs,_TNames),
2516 (call(P,Expr,TDAcc,NewAcc)
2517 -> member(Sub,Subs), map_over_bexpr_top_down_acc(P,Sub,NewAcc)
2518 ; member(Sub,Subs), map_over_bexpr_top_down_acc(P,Sub,TDAcc)
2519 ).
2520 % now a version which gets the typed predicate as argument
2521
2522 map_over_typed_bexpr_top_down_acc(P,BExpr,TDAcc) :-
2523 syntaxtraversion(BExpr,_Expr,_,_,Subs,_TNames),
2524 (call(P,BExpr,TDAcc,NewAcc)
2525 -> member(Sub,Subs), map_over_typed_bexpr_top_down_acc(P,Sub,NewAcc)
2526 ; member(Sub,Subs), map_over_typed_bexpr_top_down_acc(P,Sub,TDAcc)
2527 ).
2528
2529 % predicate P has 3 arguments: (Expr,ValueSoFar,NewValue)
2530 reduce_over_bexpr(P,BExpr,InitialValue,ResultValue) :-
2531 syntaxtraversion(BExpr,Expr,_,_,Subs,_TNames),
2532 ? call(P,Expr,InitialValue,I1), % print(reduce(P,Expr,InitialValue,I1)),nl,
2533 ? scanlist(reduce_over_bexpr(P),Subs,I1,ResultValue).
2534
2535 % apply a predicate over a syntax tree (bottom-up)
2536
2537 transform_bexpr(Pred,b(Expr,Type,Info),NewBExpr) :- !,
2538 ? syntaxtransformation(Expr,Subs,_Names,NSubs,NewExpr1),
2539 ? l_transform_bexpr(Subs,Pred,NSubs),
2540 ? (call(Pred,b(NewExpr1,Type,Info),NewBExpr) -> true ; NewBExpr = b(NewExpr1,Type,Info)).
2541 transform_bexpr(Pred,Expr,NewBExpr) :-
2542 add_internal_error('Expression not properly wrapped:',transform_bexpr(Pred,Expr,NewBExpr)),
2543 fail.
2544
2545 l_transform_bexpr([],_,[]).
2546 l_transform_bexpr([SubH|T],Pred,[TSubH|TT]) :-
2547 ? transform_bexpr(Pred,SubH,TSubH),
2548 ? l_transform_bexpr(T,Pred,TT).
2549
2550 % apply a predicate over a syntax tree (bottom-up), and provide scoping info about local ids
2551
2552 transform_bexpr_with_scoping(Pred,BExpr,NewBExpr) :-
2553 transform_bexpr_with_scoping2(Pred,BExpr,NewBExpr,[]).
2554 transform_bexpr_with_scoping2(Pred,b(Expr,Type,Info),NewBExpr,LocalIds) :-
2555 syntaxtransformation(Expr,Subs,Names,NSubs,NewExpr1),
2556 get_texpr_ids(Names,QuantifiedNewIds), list_to_ord_set(QuantifiedNewIds,SQuantifiedNewIds),
2557 ord_union(LocalIds,SQuantifiedNewIds,NewLocalIds),
2558 l_transform_bexpr_with_scoping(Subs,Pred,NSubs,NewLocalIds),
2559 (call(Pred,b(NewExpr1,Type,Info),NewBExpr,LocalIds) -> true ; NewBExpr = b(NewExpr1,Type,Info)).
2560
2561 l_transform_bexpr_with_scoping([],_,[],_).
2562 l_transform_bexpr_with_scoping([SubH|T],Pred,[TSubH|TT],LocalIds) :-
2563 transform_bexpr_with_scoping2(Pred,SubH,TSubH,LocalIds),
2564 l_transform_bexpr_with_scoping(T,Pred,TT,LocalIds).
2565
2566 % transform a predicate top-down with scoping infos
2567 % if Pred succeeds the top-down traversal stops
2568 transform_bexpr_td_with_scoping(Pred,BExpr,NewBExpr) :-
2569 ? transform_bexpr_td_with_scoping2(Pred,BExpr,NewBExpr,[]).
2570 transform_bexpr_td_with_scoping2(Pred,b(Expr,Type,Info),b(NewExpr1,Type,Info),LocalIds) :-
2571 ? (call(Pred,Expr,NewExpr1,LocalIds)
2572 -> true
2573 ? ; syntaxtransformation(Expr,Subs,Names,NSubs,NewExpr1),
2574 get_texpr_ids(Names,QuantifiedNewIds), list_to_ord_set(QuantifiedNewIds,SQuantifiedNewIds),
2575 ord_union(LocalIds,SQuantifiedNewIds,NewLocalIds),
2576 ? l_transform_bexpr_td_with_scoping(Subs,Pred,NSubs,NewLocalIds)
2577 ).
2578
2579 l_transform_bexpr_td_with_scoping([],_,[],_).
2580 l_transform_bexpr_td_with_scoping([SubH|T],Pred,[TSubH|TT],LocalIds) :-
2581 ? transform_bexpr_td_with_scoping2(Pred,SubH,TSubH,LocalIds),
2582 ? l_transform_bexpr_td_with_scoping(T,Pred,TT,LocalIds).
2583
2584
2585 % apply a predicate over a syntax tree (bottom-up) with Accumulator result
2586 % Accumulator is constructed bottom up; Pred receives *all* accumulators of sub expressions
2587
2588 transform_bexpr_with_bup_accs(Pred,b(Expr,Type,Info),NewBExpr,EmptyAcc,Acc) :-
2589 syntaxtransformation(Expr,Subs,_Names,NSubs,NewExpr1),
2590 l_transform_bexpr_with_bup_accs(Subs,Pred,NSubs,EmptyAcc,SubAccs),
2591 (call(Pred,b(NewExpr1,Type,Info),NewBExpr,SubAccs,Acc) -> true
2592 ; NewBExpr = b(NewExpr1,Type,Info), Acc = EmptyAcc).
2593
2594 l_transform_bexpr_with_bup_accs([],_,[],_,[]).
2595 l_transform_bexpr_with_bup_accs([SubH|T],Pred,[TSubH|TT],EmptyAcc,[Acc1|RestAcc]) :-
2596 transform_bexpr_with_bup_accs(Pred,SubH,TSubH,EmptyAcc,Acc1),
2597 l_transform_bexpr_with_bup_accs(T,Pred,TT,EmptyAcc,RestAcc).
2598
2599 % apply a predicate over a syntax tree (bottom-up) with Accumulator result
2600 % a single Accumulator is passed along
2601
2602 transform_bexpr_with_acc(_Pred,E,NewBExpr,InAcc,Acc) :- var(E),!,
2603 NewBExpr=E, Acc=InAcc.
2604 transform_bexpr_with_acc(Pred,b(Expr,Type,Info),NewBExpr,InAcc,Acc) :-
2605 syntaxtransformation(Expr,Subs,_Names,NSubs,NewExpr1),
2606 l_transform_bexpr_with_acc(Subs,Pred,NSubs,InAcc,SubAcc),
2607 (call(Pred,b(NewExpr1,Type,Info),NewBExpr,SubAcc,Acc) -> true
2608 ; NewBExpr = b(NewExpr1,Type,Info), Acc = SubAcc).
2609
2610 l_transform_bexpr_with_acc([],_,[],Acc,Acc).
2611 l_transform_bexpr_with_acc([SubH|T],Pred,[TSubH|TT],InAcc,ResAcc) :-
2612 transform_bexpr_with_acc(Pred,SubH,TSubH,InAcc,Acc1),
2613 l_transform_bexpr_with_acc(T,Pred,TT,Acc1,ResAcc).
2614
2615 % a non-deterministic version of this
2616 non_det_transform_bexpr_with_acc(_Pred,E,NewBExpr,InAcc,Acc) :- var(E),!,
2617 NewBExpr=E, Acc=InAcc.
2618 non_det_transform_bexpr_with_acc(Pred,b(Expr,Type,Info),NewBExpr,InAcc,Acc) :-
2619 syntaxtransformation(Expr,Subs,_Names,NSubs,NewExpr1),
2620 l_nd_transform_bexpr_with_acc(Subs,Pred,NSubs,InAcc,SubAcc),
2621 if(call(Pred,b(NewExpr1,Type,Info),NewBExpr,SubAcc,Acc),
2622 true,
2623 (NewBExpr = b(NewExpr1,Type,Info), Acc = SubAcc)).
2624
2625 l_nd_transform_bexpr_with_acc([],_,[],Acc,Acc).
2626 l_nd_transform_bexpr_with_acc([SubH|T],Pred,[TSubH|TT],InAcc,ResAcc) :-
2627 non_det_transform_bexpr_with_acc(Pred,SubH,TSubH,InAcc,Acc1),
2628 l_nd_transform_bexpr_with_acc(T,Pred,TT,Acc1,ResAcc).
2629
2630
2631 % -------------------------
2632
2633 min_max_integer_value_used(BExpr,Min,Max) :-
2634 min_max_integer_value_used(BExpr,none,none,Min,Max).
2635 min_max_integer_value_used(BExpr,IMin,IMax,Min,Max) :-
2636 reduce_over_bexpr(min_max_aux,BExpr,minmax(IMin,IMax),minmax(Min,Max)).
2637
2638 min_max_aux(sequence_extension(L),minmax(Min,Max),minmax(NMin,NMax)) :- !,
2639 length(L,Len), % we use implicitly numbers from 1..Len
2640 (number(Min),1>Min -> NMin=Min ; NMin=1),
2641 (number(Max),Len<Max -> NMax=Max ; NMax=Len).
2642 min_max_aux(integer(N),minmax(Min,Max),minmax(NMin,NMax)) :- !,
2643 (number(Min),N>Min -> NMin=Min ; NMin=N),
2644 (number(Max),N<Max -> NMax=Max ; NMax=N).
2645 min_max_aux(_,V,V).
2646
2647 % check if a B expression uses something like NAT,NAT1,INT, MAXINT or MININT.
2648 uses_implementable_integers(BExpr) :-
2649 map_over_bexpr(uses_implementable_integers_aux,BExpr).
2650
2651 uses_implementable_integers_aux(maxint).
2652 uses_implementable_integers_aux(minint).
2653 uses_implementable_integers_aux(integer_set(X)) :-
2654 (X='NAT1' ; X='NAT' ; X='INT').
2655
2656 %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
2657 % some checks
2658 check_if_typed_predicate(b(Pred,X,_)) :- ground(X), X=pred, % at runtime there can be value(X) with variables inside !
2659 syntaxelement(Pred,_,_,_,_,TypePred), (TypePred=pred -> true ; TypePred = pred/only_typecheck).
2660 check_if_typed_expression(b(Expr,Type,_)) :-
2661 syntaxelement(Expr,_,_,_,_,TypeExpr),
2662 (TypeExpr=expr -> true ; TypeExpr = expr/only_typecheck),
2663 Type \== pred, Type \== subst, ground(Type).
2664 check_if_typed_substitution(b(Subst,X,_)) :- ground(X), X=subst,
2665 syntaxelement(Subst,_,_,_,_,subst).
2666
2667 %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
2668 % transformations
2669
2670 syntaxtransformation(Expr,Subs,Names,NSubs,NExpr) :-
2671 functor(Expr,F,Arity),
2672 functor(NExpr,F,Arity),
2673 safe_syntaxelement(Expr,Subs,Names,Lists,Constant),
2674 all_same_length(Lists,NLists),
2675 ? syntaxelement(NExpr,NSubs,_,NLists,Constant,_).
2676 % a faster non-backtracking version:
2677 syntaxtransformation_det(Expr,Subs,Names,NSubs,NExpr) :-
2678 functor(Expr,F,Arity),
2679 functor(NExpr,F,Arity),
2680 safe_syntaxelement_det(Expr,Subs,Names,Lists,Constant),
2681 all_same_length(Lists,NLists),
2682 ? syntaxelement(NExpr,NSubs,_,NLists,Constant,_).
2683
2684
2685 safe_syntaxelement(Expr,Subs,Names,Lists,Constant) :-
2686 ( syntaxelement(Expr,SubsX,NamesX,Lists,ConstantX,_) ->
2687 Subs=SubsX, Names=NamesX, Constant=ConstantX
2688 %(Subs,Names,Constant)=(SubsX,NamesX,ConstantX)
2689 ;
2690 functor(Expr,F,Arity),
2691 add_error_fail(bsyntaxtree,'Uncovered syntax element: ', F/Arity)
2692 ).
2693 % a faster non-backtracking version of safe_syntaxelement, assuming Subs, Names, ... are fresh vars
2694 safe_syntaxelement_det(Expr,Subs,Names,Lists,Constant) :-
2695 (syntaxelement(Expr,Subs,Names,Lists,Constant,_) -> true
2696 ; functor(Expr,F,Arity),
2697 add_error_fail(bsyntaxtree,'Uncovered syntax element: ', F/Arity)).
2698
2699 is_subst_syntaxelement(Subst) :-
2700 syntaxelement(Subst,_,_,_,_,subst).
2701
2702 % check if we have a syntax node without parameters
2703 is_syntax_constant(Expr) :- atom(Expr), syntaxelement(Expr,_,_,_,_,_).
2704
2705 % syntaxelement(Expr,SubExprs,Identifiers,Lists,Constant,Type):
2706 % Expr: the expression itself
2707 % SubExprs: a list of sub-expressions
2708 % Identifiers: a list of identifiers that are newly introduced (e.g. by a quantifier)
2709 % Lists: A list of lists in the expression, to prevent infinite loops when having variable parts
2710 % Constant: A part of the expression that is not a sub-expression (e.g. the number in integer(...))
2711 % Type: Fundamental type of the element (predicate, expression, etc)
2712
2713 % predicates
2714 syntaxelement(truth, [], [], [], [], pred).
2715 syntaxelement(falsity, [], [], [], [], pred).
2716 syntaxelement(unknown_truth_value(Msg),[], [], [], Msg, pred). % artificial, e.g., created by well_def_analyser
2717 syntaxelement(conjunct(A,B), [A,B],[], [], [], pred).
2718 %syntaxelement(conjunct(As), As, [], [], [], pred). % TO DO: support associative version of conjunct
2719 syntaxelement(negation(A), [A], [], [], [], pred).
2720 syntaxelement(disjunct(A,B), [A,B],[], [], [], pred).
2721 syntaxelement(implication(A,B), [A,B],[], [], [], pred).
2722 syntaxelement(equivalence(A,B), [A,B],[], [], [], pred).
2723 syntaxelement(equal(A,B), [A,B],[], [], [], pred).
2724 syntaxelement(not_equal(A,B), [A,B],[], [], [], pred).
2725 syntaxelement(member(A,B), [A,B],[], [], [], pred).
2726 syntaxelement(not_member(A,B), [A,B],[], [], [], pred).
2727 syntaxelement(subset(A,B), [A,B],[], [], [], pred).
2728 syntaxelement(subset_strict(A,B), [A,B],[], [], [], pred).
2729 syntaxelement(not_subset(A,B), [A,B],[], [], [], pred).
2730 syntaxelement(not_subset_strict(A,B),[A,B],[], [], [], pred).
2731 syntaxelement(less_equal(A,B), [A,B],[], [], [], pred).
2732 syntaxelement(less(A,B), [A,B],[], [], [], pred).
2733 syntaxelement(less_equal_real(A,B), [A,B],[], [], [], pred).
2734 syntaxelement(less_real(A,B), [A,B],[], [], [], pred).
2735 syntaxelement(greater_equal(A,B), [A,B],[], [], [], pred).
2736 syntaxelement(greater(A,B), [A,B],[], [], [], pred).
2737 syntaxelement(forall(Ids,D,P), [D,P|Ids],Ids,[Ids], [], pred).
2738 syntaxelement(exists(Ids,P), [P|Ids], Ids,[Ids], [], pred).
2739 syntaxelement(finite(A), [A], [], [], [], pred/only_typecheck).
2740 syntaxelement(partition(S,Es), [S|Es],[],[Es],[],pred).
2741 syntaxelement(kodkod(PId,Ids), Ids,[],[Ids],PId, pred).
2742 syntaxelement(external_pred_call(F,Args),Args,[],[Args],F,pred).
2743
2744 % expressions
2745 syntaxelement(value(V), [], [], [], V, expr).
2746 syntaxelement(operation_call_in_expr(Id,As), As, [], [As], Id, expr). % Do not treat Id as a sub-expression for find_identifier_uses, ...
2747 %syntaxelement(operation_call_in_expr(Id,As), [Id|As], [], [As], [], expr). % was like this, but changed to avoid op(.) ids in find_identifier_uses
2748 syntaxelement(boolean_true, [], [], [], [], expr).
2749 syntaxelement(boolean_false, [], [], [], [], expr).
2750 syntaxelement(max_int, [], [], [], [], expr).
2751 syntaxelement(min_int, [], [], [], [], expr).
2752 syntaxelement(empty_set, [], [], [], [], expr).
2753 syntaxelement(bool_set, [], [], [], [], expr).
2754 syntaxelement(float_set, [], [], [], [], expr).
2755 syntaxelement(real(I), [], [], [], I, expr).
2756 syntaxelement(real_set, [], [], [], [], expr).
2757 syntaxelement(string_set, [], [], [], [], expr).
2758 syntaxelement(convert_bool(A), [A], [], [], [], expr).
2759 syntaxelement(convert_real(A), [A], [], [], [], expr).
2760 syntaxelement(convert_int_floor(A), [A], [], [], [], expr).
2761 syntaxelement(convert_int_ceiling(A), [A], [], [], [], expr).
2762 syntaxelement(add(A,B), [A,B],[], [], [], expr).
2763 syntaxelement(add_real(A,B), [A,B],[], [], [], expr).
2764 syntaxelement(minus(A,B), [A,B],[], [], [], expr).
2765 syntaxelement(minus_real(A,B), [A,B],[], [], [], expr).
2766 syntaxelement(minus_or_set_subtract(A,B),[A,B],[], [], [], expr/only_typecheck).
2767 syntaxelement(unary_minus(A), [A], [], [], [], expr).
2768 syntaxelement(unary_minus_real(A), [A], [], [], [], expr).
2769 syntaxelement(multiplication(A,B), [A,B],[], [], [], expr).
2770 syntaxelement(multiplication_real(A,B),[A,B],[], [], [], expr).
2771 syntaxelement(mult_or_cart(A,B), [A,B],[], [], [], expr/only_typecheck).
2772 syntaxelement(cartesian_product(A,B), [A,B],[], [], [], expr).
2773 syntaxelement(div(A,B), [A,B],[], [], [], expr).
2774 syntaxelement(div_real(A,B), [A,B],[], [], [], expr).
2775 syntaxelement(floored_div(A,B), [A,B],[], [], [], expr).
2776 syntaxelement(modulo(A,B), [A,B],[], [], [], expr).
2777 syntaxelement(power_of(A,B), [A,B],[], [], [], expr).
2778 syntaxelement(power_of_real(A,B), [A,B],[], [], [], expr).
2779 syntaxelement(successor, [], [], [], [], expr).
2780 syntaxelement(predecessor, [], [], [], [], expr).
2781 syntaxelement(max(A), [A], [], [], [], expr).
2782 syntaxelement(max_real(A), [A], [], [], [], expr).
2783 syntaxelement(min(A), [A], [], [], [], expr).
2784 syntaxelement(min_real(A), [A], [], [], [], expr).
2785 syntaxelement(card(A), [A], [], [], [], expr).
2786 syntaxelement(couple(A,B), [A,B],[], [], [], expr).
2787 syntaxelement(pow_subset(A), [A], [], [], [], expr).
2788 syntaxelement(pow1_subset(A), [A], [], [], [], expr).
2789 syntaxelement(fin_subset(A), [A], [], [], [], expr).
2790 syntaxelement(fin1_subset(A), [A], [], [], [], expr).
2791 syntaxelement(interval(A,B), [A,B],[], [], [], expr).
2792 syntaxelement(union(A,B), [A,B],[], [], [], expr).
2793 syntaxelement(intersection(A,B), [A,B],[], [], [], expr).
2794 syntaxelement(set_subtraction(A,B), [A,B],[], [], [], expr).
2795 syntaxelement(general_union(A), [A], [], [], [], expr).
2796 syntaxelement(general_intersection(A), [A] , [], [], [], expr).
2797 syntaxelement(relations(A,B), [A,B],[], [], [], expr).
2798 syntaxelement(identity(A), [A], [], [], [], expr).
2799 syntaxelement(event_b_identity, [], [], [], [], expr). % for Rodin 1.0, TO DO: Daniel please check
2800 syntaxelement(reverse(A), [A], [], [], [], expr).
2801 syntaxelement(first_projection(A,B), [A,B],[], [], [], expr/only_typecheck).
2802 syntaxelement(first_of_pair(A), [A], [], [], [], expr).
2803 syntaxelement(event_b_first_projection(A),[A], [], [], [], expr/only_typecheck).
2804 syntaxelement(event_b_first_projection_v2,[], [], [], [], expr/only_typecheck). % for Rodin 1.0, TO DO: Daniel please check
2805 syntaxelement(second_projection(A,B), [A,B],[], [], [], expr/only_typecheck).
2806 syntaxelement(event_b_second_projection_v2,[], [], [], [], expr/only_typecheck). % for Rodin 1.0, TO DO: Daniel please check
2807 syntaxelement(second_of_pair(A), [A], [], [], [], expr).
2808 syntaxelement(event_b_second_projection(A),[A], [], [], [], expr/only_typecheck).
2809 syntaxelement(composition(A,B), [A,B],[], [], [], expr).
2810 syntaxelement(ring(A,B), [A,B],[], [], [], expr/only_typecheck).
2811 syntaxelement(direct_product(A,B), [A,B],[], [], [], expr).
2812 syntaxelement(parallel_product(A,B), [A,B],[], [], [], expr).
2813 syntaxelement(trans_function(A), [A], [], [], [], expr).
2814 syntaxelement(trans_relation(A), [A], [], [], [], expr).
2815 syntaxelement(iteration(A,B), [A,B],[], [], [], expr).
2816 syntaxelement(reflexive_closure(A), [A], [], [], [], expr).
2817 syntaxelement(closure(A), [A], [], [], [], expr).
2818 syntaxelement(domain(A), [A], [], [], [], expr).
2819 syntaxelement(range(A), [A], [], [], [], expr).
2820 syntaxelement(image(A,B), [A,B],[], [], [], expr).
2821 syntaxelement(domain_restriction(A,B), [A,B],[], [], [], expr).
2822 syntaxelement(domain_subtraction(A,B), [A,B],[], [], [], expr).
2823 syntaxelement(range_restriction(A,B), [A,B],[], [], [], expr).
2824 syntaxelement(range_subtraction(A,B), [A,B],[], [], [], expr).
2825 syntaxelement(overwrite(A,B), [A,B],[], [], [], expr).
2826 syntaxelement(partial_function(A,B), [A,B],[], [], [], expr).
2827 syntaxelement(total_function(A,B), [A,B],[], [], [], expr).
2828 syntaxelement(partial_injection(A,B), [A,B],[], [], [], expr).
2829 syntaxelement(total_injection(A,B), [A,B],[], [], [], expr).
2830 syntaxelement(partial_surjection(A,B), [A,B],[], [], [], expr).
2831 syntaxelement(total_surjection(A,B), [A,B],[], [], [], expr).
2832 syntaxelement(total_bijection(A,B), [A,B],[], [], [], expr).
2833 syntaxelement(partial_bijection(A,B), [A,B],[], [], [], expr).
2834 syntaxelement(total_relation(A,B), [A,B],[], [], [], expr).
2835 syntaxelement(surjection_relation(A,B),[A,B],[], [], [], expr).
2836 syntaxelement(total_surjection_relation(A,B),[A,B],[], [], [], expr).
2837 syntaxelement(seq(A), [A], [], [], [], expr).
2838 syntaxelement(seq1(A), [A], [], [], [], expr).
2839 syntaxelement(iseq(A), [A], [], [], [], expr).
2840 syntaxelement(iseq1(A), [A], [], [], [], expr).
2841 syntaxelement(perm(A), [A], [], [], [], expr).
2842 syntaxelement(empty_sequence, [], [], [], [], expr).
2843 syntaxelement(size(A), [A], [], [], [], expr).
2844 syntaxelement(first(A), [A], [], [], [], expr).
2845 syntaxelement(last(A), [A], [], [], [], expr).
2846 syntaxelement(front(A), [A], [], [], [], expr).
2847 syntaxelement(tail(A), [A], [], [], [], expr).
2848 syntaxelement(rev(A), [A], [], [], [], expr).
2849 syntaxelement(concat(A,B), [A,B],[], [], [], expr).
2850 syntaxelement(insert_front(A,B), [A,B],[], [], [], expr).
2851 syntaxelement(insert_tail(A,B), [A,B],[], [], [], expr).
2852 syntaxelement(restrict_front(A,B), [A,B],[], [], [], expr).
2853 syntaxelement(restrict_tail(A,B), [A,B],[], [], [], expr).
2854 syntaxelement(general_concat(A), [A], [], [], [], expr).
2855 syntaxelement(function(A,B), [A,B],[], [], [], expr).
2856 syntaxelement(external_function_call(F,Args),Args,[],[Args],F,expr).
2857 syntaxelement(identifier(I), [], [], [], I, expr).
2858 syntaxelement(lazy_lookup_expr(I), [], [], [], I, expr).
2859 syntaxelement(lazy_lookup_pred(I), [], [], [], I, pred).
2860 syntaxelement(integer(I), [], [], [], I, expr).
2861 syntaxelement(integer_set(T), [], [], [], T, expr).
2862 syntaxelement(string(S), [], [], [], S, expr).
2863 syntaxelement(set_extension(L), L, [], [L], [], expr).
2864 syntaxelement(sequence_extension(L), L, [], [L], [], expr).
2865 syntaxelement(comprehension_set(Ids,P),[P|Ids], Ids,[Ids], [], expr).
2866 syntaxelement(event_b_comprehension_set(Ids,E,P),[E,P|Ids], Ids,[Ids], [], expr/only_typecheck).
2867 syntaxelement(lambda(Ids,P,E), [P,E|Ids],Ids,[Ids], [], expr).
2868 syntaxelement(general_sum(Ids,P,E), [P,E|Ids],Ids,[Ids], [], expr).
2869 syntaxelement(general_product(Ids,P,E), [P,E|Ids],Ids,[Ids], [], expr).
2870 syntaxelement(quantified_union(Ids,P,E), [P,E|Ids],Ids,[Ids], [], expr).
2871 syntaxelement(quantified_intersection(Ids,P,E), [P,E|Ids],Ids,[Ids], [], expr).
2872 syntaxelement(struct(Rec), [Rec], [], [], [], expr).
2873 ?syntaxelement(rec(Fields), FContent, [], [FContent], FNames, expr) :- syntaxfields(Fields,FContent, FNames).
2874 syntaxelement(record_field(R,I), [R], [], [], I, expr).
2875 syntaxelement(assertion_expression(Cond,ErrMsg,Expr), [Cond,Expr], [], [], ErrMsg, expr).
2876 syntaxelement(typeset, [], [], [], [], expr/only_typecheck).
2877
2878 syntaxelement(tree(A), [A], [], [], [], expr).
2879 syntaxelement(btree(A), [A], [], [], [], expr).
2880 syntaxelement(const(A,B), [A,B],[], [], [], expr).
2881 syntaxelement(top(A), [A], [], [], [], expr).
2882 syntaxelement(sons(A), [A], [], [], [], expr).
2883 syntaxelement(prefix(A), [A], [], [], [], expr).
2884 syntaxelement(postfix(A), [A], [], [], [], expr).
2885 syntaxelement(sizet(A), [A], [], [], [], expr).
2886 syntaxelement(mirror(A), [A], [], [], [], expr).
2887 syntaxelement(rank(A,B), [A,B],[], [], [], expr).
2888 syntaxelement(father(A,B), [A,B],[], [], [], expr).
2889 syntaxelement(son(A,B,C), [A,B,C],[], [], [], expr).
2890 syntaxelement(subtree(A,B), [A,B],[], [], [], expr).
2891 syntaxelement(arity(A,B), [A,B],[], [], [], expr).
2892 syntaxelement(bin(A), [A],[], [], [], expr).
2893 syntaxelement(bin(A,B,C), [A,B,C],[], [], [], expr).
2894 syntaxelement(infix(A), [A], [], [], [], expr).
2895 syntaxelement(left(A), [A], [], [], [], expr).
2896 syntaxelement(right(A), [A], [], [], [], expr).
2897
2898 % substitutions
2899 syntaxelement(skip, [], [], [], [], subst).
2900 syntaxelement(precondition(A,B), [A,B],[], [], [], subst).
2901 syntaxelement(assertion(A,B), [A,B],[], [], [], subst).
2902 syntaxelement(witness_then(A,B), [A,B],[], [], [], subst).
2903 syntaxelement(if_elsif(A,B), [A,B],[], [], [], subst/elsif).
2904 syntaxelement(while(A,B,C,D), [A,B,C,D],[], [], [], subst).
2905 % used only internally in the interpreter, contains last value of variant:
2906 syntaxelement(while1(A,B,C,D,E), [A,B,C,D],[], [], E, subst).
2907 syntaxelement(select_when(A,B), [A,B],[], [], [], subst/when).
2908 syntaxelement(block(S),[S],[],[],[], subst/only_typecheck).
2909 syntaxelement(assign(Lhs,Rhs),Exprs,[],[Lhs,Rhs], [], subst) :- append(Lhs,Rhs,Exprs).
2910 syntaxelement(assign_single_id(Id,Rhs),[Id,Rhs],[],[], [], subst).
2911 syntaxelement(any(Ids,P,S),[P,S|Ids],Ids,[Ids], [], subst).
2912 syntaxelement(var(Ids,S), [S|Ids], Ids,[Ids], [], subst).
2913 syntaxelement(if(Ifs), Ifs, [], [Ifs], [], subst).
2914 syntaxelement(parallel(Ss), Ss, [], [Ss], [], subst).
2915 syntaxelement(sequence(Ss), Ss, [], [Ss], [], subst).
2916 syntaxelement(becomes_element_of(Ids,E), [E|Ids], [], [Ids], [], subst).
2917 syntaxelement(becomes_such(Ids,P), [P|Ids], [], [Ids], [], subst). % Ids are new value, Ids$0 is old value
2918 syntaxelement(evb2_becomes_such(Ids,P), [P|Ids], [], [Ids], [], subst/only_typecheck).
2919 syntaxelement(let(Ids,P,S), [P,S|Ids], Ids, [Ids], [], subst).
2920 syntaxelement(operation_call(Id,Rs,As), [Id|Exprs], [], [Rs,As], [], subst) :- append(Rs,As,Exprs).
2921 syntaxelement(case(E,Eithers,Else), [E,Else|Eithers], [], [Eithers], [], subst).
2922 syntaxelement(case_or(Es,S), [S|Es], [], [Es], [], subst/caseor).
2923 syntaxelement(choice(Ss), Ss, [], [Ss], [], subst).
2924 syntaxelement(select(Whens), Whens, [], [Whens], [], subst).
2925 syntaxelement(select(Whens,Else), [Else|Whens], [], [Whens], [], subst).
2926 syntaxelement(operation(I,Rs,As,B), [I,B|Ids], Ids, [Rs,As], [], subst) :- append(Rs,As,Ids).
2927 syntaxelement(external_subst_call(F,Args),Args,[],[Args],F,subst).
2928
2929 % elements of a VALUES clause
2930 syntaxelement(values_entry(I,E),[I,E],[],[],[],values_entry).
2931
2932 % syntax for Event-B events
2933 syntaxelement(rlevent(I,Sec,St,Ps,G,Ts,As,VWs,PWs,Ums,Rs), Subs, [], [Ps,Ts,As,VWs,PWs,Ums,Rs], [I,Sec], subst) :-
2934 append([[St],Ps,[G],Ts,As,VWs,PWs,Ums,Rs],Subs).
2935 syntaxelement(witness(I,P), [I,P], [], [], [], witness).
2936
2937 % extended syntax for Z
2938 syntaxelement(let_predicate(Ids,As,Pred), Exprs, Ids, [Ids,As], [], pred) :- append([Ids,As,[Pred]],Exprs).
2939 syntaxelement(let_expression(Ids,As,Expr), Exprs, Ids, [Ids,As], [], expr) :- append([Ids,As,[Expr]],Exprs).
2940 syntaxelement(let_expression_global(Ids,As,Expr), Exprs, Ids, [Ids,As], [], expr) :- % version used by b_compiler
2941 append([Ids,As,[Expr]],Exprs).
2942 syntaxelement(lazy_let_expr(TID,A,Expr), [TID, A, Expr], [TID], [[TID],[A]], [], expr).
2943 syntaxelement(lazy_let_pred(TID,A,Expr), [TID, A, Expr], [TID], [[TID],[A]], [], pred).
2944 syntaxelement(lazy_let_subst(TID,A,Expr), [TID, A, Expr], [TID], [[TID],[A]], [], subst).
2945 syntaxelement(if_then_else(If,Then,Else),[If,Then,Else], [], [], [], expr).
2946 syntaxelement(compaction(A), [A], [], [], [], expr).
2947 syntaxelement(mu(A), [A], [], [], [], expr).
2948 syntaxelement(bag_items(A), [A], [], [], [], expr).
2949
2950 syntaxelement(freetype_set(Id), [], [], [], Id, expr).
2951 syntaxelement(freetype_case(Type,Case,Expr), [Expr], [], [], [Type,Case], pred).
2952 syntaxelement(freetype_constructor(Type,Case,Expr), [Expr], [], [], [Type,Case], expr).
2953 syntaxelement(freetype_destructor(Type,Case,Expr), [Expr], [], [], [Type,Case], expr).
2954
2955 syntaxelement(ordinary, [], [], [], [], status).
2956 syntaxelement(anticipated(Variant), [Variant], [], [], [], status).
2957 syntaxelement(convergent(Variant), [Variant], [], [], [], status).
2958
2959 % Just one ID expected
2960 syntaxelement(recursive_let(Id,C),[Id,C],[Id],[],[], expr). % Note: Id is not really introduced !
2961
2962
2963 % fields of records
2964 %syntaxfields(Fields,C,_) :- var(Fields),var(C),var(N),!, add_internal_error('Illegal call: ',syntaxfields(Fields,C,N)),fail.
2965 syntaxfields([],[],[]).
2966 ?syntaxfields([field(N,C)|Rest],[C|CRest],[N|NRest]) :- syntaxfields(Rest,CRest,NRest).
2967
2968 %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
2969 % helper for declaration of quantified identifiers
2970
2971 % has_declared_identifier/2 returns a list of identifiers which are declared in
2972 % this AST node. The main difference to the Names variable when doing a
2973 % syntaxtraversion/6 or similiar is that the identifiers are described by
2974 % predicates.
2975 has_declared_identifier(TExpr,Ids) :-
2976 get_texpr_expr(TExpr,Expr),
2977 ( default_declaration(Expr,_,Ids,_)
2978 ; non_default_declaration(Expr,Ids)).
2979
2980 add_declaration_for_identifier(b(Expr,Type,Infos),Decl,b(NExpr,Type,NewInfos)) :-
2981 %delete(Infos,used_ids(_),NewInfos), % we cannot
2982 ( default_declaration(Expr,Predicate,Ids,Constant) ->
2983 same_functor(Expr,NExpr),
2984 conjunct_predicates([Decl,Predicate],NPredicate),
2985 default_declaration(NExpr,NPredicate,Ids,Constant)
2986 ; non_default_declaration(Expr,Ids) ->
2987 add_non_default_declaration(Expr,Decl,NExpr)
2988 ),
2989 add_used_ids(Infos,Ids,Decl,NewInfos).
2990
2991 % add used ids of a predicate within quantification of Ids to current used_ids info; if it is there
2992 add_used_ids(Infos,Ids,Pred,NewInfos) :- update_used_ids(Infos,OldUsed,NewInfos,NewUsed),
2993 !, % a field needs updating
2994 find_identifier_uses(Pred,[],NewIds), get_texpr_ids(Ids,UnsortedIds),sort(UnsortedIds,SIds),
2995 ord_subtract(NewIds,SIds,NewIds2),
2996 ord_union(NewIds2,OldUsed,NewUsed).
2997 add_used_ids(I,_,_,I).
2998
2999 % just update used_ids field (e.g., when just computed to store it for later)
3000 ?update_used_ids(Infos,OldUsed,NewInfos,NewUsed) :- select(OldInfo,Infos,I1),
3001 used_ids_like_info(OldInfo,F,OldUsed),!,
3002 used_ids_like_info(NewInfo,F,NewUsed),NewInfos = [NewInfo|I1].
3003
3004 % info fields which contain used_ids information
3005 used_ids_like_info(used_ids(UsedIds),used_ids,UsedIds).
3006 used_ids_like_info(reads(UsedIds),reads,UsedIds).
3007
3008 :- use_module(probsrc(btypechecker), [prime_identifiers/2]).
3009
3010 % default_declaration(Expr,Predicate,Ids,Constant)
3011 default_declaration(forall(Ids,D,P),D,Ids,P).
3012 default_declaration(exists(Ids,P),P,Ids,[]).
3013 default_declaration(comprehension_set(Ids,P),P,Ids,[]).
3014 default_declaration(event_b_comprehension_set(Ids,E,P),P,Ids,E). % translated !?
3015 default_declaration(lambda(Ids,P,E),P,Ids,E).
3016 default_declaration(general_sum(Ids,P,E),P,Ids,E).
3017 default_declaration(general_product(Ids,P,E),P,Ids,E).
3018 default_declaration(quantified_union(Ids,P,E),P,Ids,E).
3019 default_declaration(quantified_intersection(Ids,P,E),P,Ids,E).
3020 default_declaration(any(Ids,P,S),P,Ids,S).
3021 default_declaration(becomes_such(Ids,P),P,Ids,[]).
3022 default_declaration(evb2_becomes_such(Ids,P),P,Primed,[]) :-
3023 nl,print(evb2(Ids,Primed)),nl,nl, % no longer used, as it is translated to becomes_such
3024 prime_identifiers(Ids,Primed).
3025 default_declaration(rlevent(I,Sec,St,Ps,G,Ts,As,VWs,PWs,Ums,Rs),G,Ps,
3026 [I,Sec,St,Ps,Ts,As,VWs,PWs,Ums,Rs]).
3027 default_declaration(let_predicate(Ids,Ps,Body),Ps,Ids,Body) :- print(let(Ids)),nl. % TODO: check format of Ps
3028 default_declaration(let_expression(Ids,Ps,Body),Ps,Ids,Body) :- print(let(Ids)),nl. % TODO: check format of Ps
3029 default_declaration(let_expression_global(Ids,Ps,Body),Ps,Ids,Body) :- print(let(Ids)),nl. % TODO: check format of Ps
3030 % TODO: lazy let ?
3031
3032 non_default_declaration(operation(_I,Rs,As,_TBody),Ids) :-
3033 append(Rs,As,Ids).
3034
3035 add_non_default_declaration(operation(I,Rs,As,TBody),Decl,operation(I,Rs,As,NTBody)) :-
3036 ( get_guard_and_copy(TBody,P,NP,NTBody) ->
3037 conjunct_predicates([Decl,P],NP)
3038 ; create_texpr(precondition(Decl,TBody),subst,[],NTBody)).
3039
3040 get_guard_and_copy(TBody,P,NP,NTBody) :- remove_bt(TBody,Body,NBody,NTBody),
3041 get_guard_copy2(Body,P,NP,NBody).
3042
3043 get_guard_copy2(precondition(P,S),P,NP,precondition(NP,S)).
3044 get_guard_copy2(rlevent(I,Sec,St,Ps, G,Ts,As,VWs,PWs,Ums,Rs), G, NG,
3045 rlevent(I,Sec,St,Ps,NG,Ts,As,VWs,PWs,Ums,Rs)).
3046
3047 %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
3048 % pattern definitions (not yet finished)
3049
3050 bsyntax_pattern(Expr,TExpr) :-
3051 var(Expr),!,Expr=TExpr.
3052 bsyntax_pattern(-Expr,TExpr) :-
3053 !,remove_all_infos(Expr,TExpr).
3054 bsyntax_pattern(Expr,TExpr) :-
3055 functor(Expr,b,3),!,Expr=TExpr.
3056 bsyntax_pattern(Expr:Type/Info,TExpr) :-
3057 !,bsyntax_pattern2(Expr,Type,Info,TExpr).
3058 bsyntax_pattern(Expr:Type,TExpr) :-
3059 !,bsyntax_pattern2(Expr,Type,_Info,TExpr).
3060 bsyntax_pattern(Expr/Info,TExpr) :-
3061 !,bsyntax_pattern2(Expr,_Type,Info,TExpr).
3062 bsyntax_pattern(Expr,TExpr) :-
3063 !,bsyntax_pattern2(Expr,_Type,_Info,TExpr).
3064
3065 bsyntax_pattern2(Pattern,Type,Info,TExpr) :-
3066 functor(Pattern,Functor,Arity),
3067 functor(R,Functor,Arity),
3068 create_texpr(R,Type,Info,TExpr),
3069 syntaxelement(Pattern,PSubs,_,PLists,Const,EType),
3070 syntaxelement(R,RSubs,_,RLists,Const,EType),
3071 ( EType==pred -> Type=pred
3072 ; EType==subst -> Type=subst
3073 ; true),
3074 all_same_length(PLists,RLists),
3075 maplist(bsyntax_pattern,PSubs,RSubs).
3076
3077 all_same_length([],[]).
3078 all_same_length([A|Arest],[B|Brest]) :-
3079 ( var(A),var(B) ->
3080 add_error_fail(bsyntaxtree,'At least one list should contain nonvar elements for all_same_length',[A,B])
3081 ;
3082 same_length(A,B)),
3083 all_same_length(Arest,Brest).
3084
3085 %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
3086 % strip an AST into a more compact form (without b/3 terms)
3087
3088 strip_and_norm_ast(TExpr,SNExpr) :-
3089 get_texpr_expr(TExpr,Expr),
3090 ? strip_and_norm_ast_aux(Expr,SNExpr).
3091
3092 :- use_module(tools,[safe_univ_no_cutoff/2]).
3093 strip_and_norm_ast_aux(Expr,Res) :-
3094 comm_assoc_subs(Expr,Op,Subs,[]), !, % associative & commutative operator detected
3095 ? maplist(strip_and_norm_ast_aux,Subs,NSubs), % Subs are already unwrapped
3096 sort(NSubs,Sorted), % in case there are associative operators that are not commutative: insert is_commutative check
3097 safe_univ_no_cutoff(Res,[Op|Sorted]).
3098 strip_and_norm_ast_aux(Expr,Res) :-
3099 assoc_subs(Expr,Op,Subs,[]), !, % associative operator detected
3100 maplist(strip_and_norm_ast_aux,Subs,NSubs), % Subs are already unwrapped
3101 safe_univ_no_cutoff(Res,[Op|NSubs]).
3102 strip_and_norm_ast_aux(Expr,SNExpr) :-
3103 ? syntaxtransformation(Expr,Subs,_,NSubs,SExpr),
3104 ? strip_and_norm_ast_l(Subs,NSubs),
3105 norm_strip(SExpr,SNExpr).
3106
3107 strip_and_norm_ast_l([],[]).
3108 strip_and_norm_ast_l([TExpr|Trest],[NExpr|Nrest]) :-
3109 ? strip_and_norm_ast(TExpr,NExpr),
3110 ? strip_and_norm_ast_l(Trest,Nrest).
3111
3112 norm_strip(greater_equal(A,B),less_equal(B,A)) :- !.
3113 norm_strip(greater(A,B),less(B,A)) :- !.
3114 norm_strip(set_extension(NL),set_extension(SNL)) :- !,
3115 sort(NL,SNL).
3116 norm_strip(Old,New) :-
3117 functor(Old,Functor,2),
3118 is_commutative(Functor),!,
3119 arg(1,Old,OA),
3120 arg(2,Old,OB),
3121 ( OA @> OB -> New =.. [Functor,OB,OA]
3122 ; New=Old).
3123 norm_strip(Old,Old).
3124 % TO DO: flatten associative operators into lists !
3125
3126 comm_assoc_subs(conjunct(TA,TB),conjunct) --> !,
3127 {get_texpr_expr(TA,A), get_texpr_expr(TB,B)},
3128 comm_assoc_subs(A,conjunct), comm_assoc_subs(B,conjunct).
3129 comm_assoc_subs(disjunct(TA,TB),disjunct) --> !,
3130 {get_texpr_expr(TA,A), get_texpr_expr(TB,B)},
3131 comm_assoc_subs(A,disjunct), comm_assoc_subs(B,disjunct).
3132 comm_assoc_subs(add(TA,TB),add) --> !,
3133 {get_texpr_expr(TA,A), get_texpr_expr(TB,B)},
3134 comm_assoc_subs(A,add), comm_assoc_subs(B,add).
3135 comm_assoc_subs(multiplication(TA,TB),multiplication) --> !,
3136 {get_texpr_expr(TA,A), get_texpr_expr(TB,B)},
3137 comm_assoc_subs(A,multiplication), comm_assoc_subs(B,multiplication).
3138 comm_assoc_subs(union(TA,TB),union) --> !,
3139 {get_texpr_expr(TA,A), get_texpr_expr(TB,B)},
3140 comm_assoc_subs(A,union), comm_assoc_subs(B,union).
3141 comm_assoc_subs(intersection(TA,TB),intersection) --> !,
3142 {get_texpr_expr(TA,A), get_texpr_expr(TB,B)},
3143 comm_assoc_subs(A,intersection), comm_assoc_subs(B,intersection).
3144 comm_assoc_subs(Expr,Op) --> {nonvar(Op)},[Expr]. % base case for other operators
3145
3146 % detect just associative operators
3147 assoc_subs(concat(TA,TB),concat) --> !,
3148 {get_texpr_expr(TA,A), get_texpr_expr(TB,B)},
3149 assoc_subs(A,concat), assoc_subs(B,concat).
3150 assoc_subs(composition(TA,TB),composition) --> !,
3151 {get_texpr_expr(TA,A), get_texpr_expr(TB,B)},
3152 assoc_subs(A,composition), assoc_subs(B,composition).
3153 assoc_subs(Expr,Op) --> {nonvar(Op)},[Expr]. % base case for other operators
3154
3155 is_commutative(conjunct).
3156 is_commutative(disjunct).
3157 is_commutative(equivalence).
3158 is_commutative(equal).
3159 is_commutative(not_equal).
3160 is_commutative(add).
3161 is_commutative(multiplication).
3162 is_commutative(union).
3163 is_commutative(intersection).
3164
3165 % check if two type expressions are same modulo info fields and reordering of commutative operators
3166 % same_texpr does not reorder wrt commutativity.
3167 same_norm_texpr(TExpr1,TExpr2) :-
3168 ? strip_and_norm_ast(TExpr1,N1),
3169 strip_and_norm_ast(TExpr2,N1).
3170
3171
3172 % small utility to get functor of texpr:
3173 get_texpr_functor(b(E,_,_),F,N) :- !, functor(E,F,N).
3174 get_texpr_functor(E,_,+) :- add_error_fail(get_texpr_functor,'Not a typed expression: ',E).
3175
3176 % -------------------------
3177
3178 % check if a ProB type is a set type:
3179 is_set_type(set(Type),Type).
3180 is_set_type(seq(Type),couple(integer,Type)).
3181 % should we have a rule for any ?? : in all cases using is_set_type any seems not possible; better that we generate error message in get_set_type or get_texpr_set_type
3182 % is_set_type(any,any).
3183
3184 get_set_type(TypeX,Res) :-
3185 ? (is_set_type(TypeX,SetType) -> Res=SetType ; add_error_fail(get_set_type,'Not a set type: ',TypeX)).
3186
3187 get_texpr_set_type(X,Res) :- get_texpr_type(X,TypeX),
3188 get_set_type(TypeX,Res).
3189
3190
3191 %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
3192 % check if a set contains all elements of a type, i.e., maximal type
3193 is_just_type(Expr) :- is_just_type(Expr,[]).
3194 % is_just_type(+Expr,+RTT):
3195 % like is_just_type/1 but RTT is a list of identifiers (without type information)
3196 % of variables or constants that are known to be types, too.
3197 % E.g. is_just_type(a ** INTEGER) would fail but is_just_type(a ** INTEGER,[a]) would
3198 % succeed.
3199 is_just_type(b(E,T,I),RTT) :- is_just_type3(E,T,I,RTT).
3200
3201
3202 is_just_type3(identifier(G),SType,Infos,RefsToTypes) :-
3203 nonvar(SType), SType = set(Type), nonvar(Type),
3204 ( Type = global(G),
3205 memberchk(given_set,Infos) % no accidental local variable G that hides global G
3206 ; memberchk(G,RefsToTypes) -> true
3207 %; Type = freetype(G),
3208 % memberchk(given_set,Infos) % no accidental local variable G that hides global G
3209 % TODO: we do not know if the Freetype has restrictions (which are encoded in the PROPERTIES)
3210 ),!.
3211 is_just_type3(freetype_set(_),_,_,_).
3212 is_just_type3(pow_subset(E),_,_,RTT) :- is_just_type(E,RTT).
3213 is_just_type3(fin_subset(E),T,_,RTT) :-
3214 is_finite_type_in_context(proving,T), % animation or proving
3215 is_just_type(E,RTT).
3216 is_just_type3(integer_set('INTEGER'),set(integer),_,_).
3217 is_just_type3(bool_set,set(boolean),_,_).
3218 is_just_type3(real_set,set(real),_,_).
3219 is_just_type3(string_set,set(string),_,_).
3220 is_just_type3(cartesian_product(A,B),_,_,RTT) :-
3221 is_just_type(A,RTT),is_just_type(B,RTT).
3222 is_just_type3(mult_or_cart(A,B),_,_,RTT) :- % is_just_type/1 could be called before the cleanup
3223 is_just_type(A,RTT),is_just_type(B,RTT). % of an expression has finished
3224 is_just_type3(relations(A,B),_,_,RTT) :-
3225 is_just_type(A,RTT),is_just_type(B,RTT).
3226 is_just_type3(struct(b(rec(Fields),_,_)),_,_,RTT) :-
3227 maplist(field_is_just_type(RTT),Fields).
3228 is_just_type3(typeset,_,_,_).
3229 is_just_type3(comprehension_set(_,b(truth,_,_)),_,_,_).
3230 is_just_type3(set_extension([V1,V2]),_,_,_) :- get_texpr_boolean(V1,B1), % TODO: also deal with enumerated set elems
3231 (B1=boolean_true -> get_texpr_boolean(V2,boolean_false) ; B1=boolean_false -> get_texpr_boolean(V2,boolean_true)).
3232 is_just_type3(value(Val),ST,_,_) :- % e.g., {TRUE,FALSE} would usually get translated into this
3233 is_set_type(ST,Type), is_maximal_value(Val,Type). % also see: quick_is_definitely_maximal_set(Val).
3234
3235 field_is_just_type(RTT,field(_,Set)) :- is_just_type(Set,RTT).
3236
3237
3238 get_texpr_boolean(b(X,_,_),Res) :- is_boolan_expr(X,Res).
3239 is_boolan_expr(boolean_true,boolean_true).
3240 is_boolan_expr(boolean_false,boolean_false).
3241 is_boolan_expr(value(X),Res) :- nonvar(X), conv_bool_val(X,Res).
3242 conv_bool_val(pred_true,boolean_true).
3243 conv_bool_val(pred_false,boolean_false).
3244
3245 :- use_module(probsrc(custom_explicit_sets),[quick_definitely_maximal_set_avl/1]).
3246 is_maximal_value(V,_) :- var(V),!,fail.
3247 is_maximal_value(global_set(GS),Type) :- (GS=='INTEGER' -> true ; Type==global(GS)).
3248 % we could call is_maximal_global_set(GS) or b_global_set (but requires compiled)
3249 is_maximal_value(avl_set(A),Type) :-
3250 type_finite_and_pre_compiled(Type),
3251 quick_definitely_maximal_set_avl(A). % note: affects test 2392
3252
3253 :- use_module(probsrc(b_global_sets),[b_global_sets_precompiled/0, enumerated_sets_precompiled/0, enumerated_set/1]).
3254 type_finite_and_pre_compiled(boolean).
3255 type_finite_and_pre_compiled(global(GS)) :-
3256 (enumerated_set(GS) -> true % at least added with pre_register_enumerated_set_with_elems
3257 ; b_global_sets_precompiled).
3258 type_finite_and_pre_compiled(couple(A,B)) :- type_finite_and_pre_compiled(A), type_finite_and_pre_compiled(B).
3259 type_finite_and_pre_compiled(set(A)) :- type_finite_and_pre_compiled(A).
3260 % TODO: records?? less-likely we have an exhaustive list
3261
3262 % Generate a custom matching / visitor predicate
3263 % bsyntaxtree:gen_visitor(bexpr_variables_aux,bexpr_variables)
3264 /*
3265 gen_visitor(Pred, BodyPred) :- syntaxelement(Expr,SubsX,_NamesX,_Lists,_ConstantX,_),
3266 print_clause(Pred,BodyPred,Expr,SubsX),
3267 fail.
3268 gen_visitor(Pred, BodyPred) :- nl.
3269
3270 print_clause(Pred,BodyPred,Expr,SubsX) :- E=..[Op|SubsX], format('~w(~w) :- ',[Pred,Expr]).
3271 */
3272
3273 /*
3274 * create_recursive_compset(+Ids,+Cond,+Type,+Infos,-RecId,-TCompSet)
3275 * creates a recursive comprehension set:
3276 * Ids is the list of the introduced typed identifiers
3277 * Cond is the condition (a typed predicate)
3278 * Infos are additional informations for the comprehension set syntax element
3279 * RecId is the identifier (untyped, an atom) that can be used in Cond to refer to the
3280 * comprehension set recursively. Usually RecId is used in Cond as a variable
3281 * TCompSet is the generated recursive comprehension set, the recursion parameter is introduced
3282 * by a recusive(Id,CompSet) syntax element
3283 */
3284 create_recursive_compset(Ids,Cond,Type,Infos,RecId,TCompSet) :-
3285 unique_id("recursive.",RecId),
3286 add_symbolic_annotation(Infos,RInfos),
3287 create_texpr(comprehension_set(Ids,Cond),Type,RInfos,TCompSet1),
3288 create_typed_id(RecId,Type,TRecId),
3289 create_texpr(recursive_let(TRecId,TCompSet1),Type,[],TCompSet).
3290
3291 unique_typed_id(Prefix,Type,TId) :-
3292 unique_id(Prefix,Id),
3293 create_typed_id(Id,Type,TId).
3294
3295
3296 mark_bexpr_as_symbolic(b(E,T,I),b(E2,T,RI)) :-
3297 add_symbolic_annotation(I,RI),
3298 mark_aux(E,E2).
3299 mark_aux(union(A,B),R) :- !, R=union(SA,SB),
3300 mark_bexpr_as_symbolic(A,SA), mark_bexpr_as_symbolic(B,SB).
3301 % union is currently the only operator that is kept symbolically
3302 mark_aux(A,A).
3303
3304 add_symbolic_annotation([H|I],R) :- H == prob_annotation('SYMBOLIC'),!, R=[H|I].
3305 add_symbolic_annotation(I,R) :- !, R=[prob_annotation('SYMBOLIC')|I].
3306
3307 % identifier_sub_ast(+TExpr,+Identifier,-SubPosition):
3308 % Find occurences of an identifier "Identifier" in an expression "TExpr"
3309 % Returns a list of positions (beginning with 0) that describes the position of a sub-expression
3310 % that contains all occurrences of Identifier in TExpr.
3311 % E.g. [1,0,1] means "second sub-expression of TExpr, then the first sub-expression of that,
3312 % then the second sub-expression of that".
3313 % When an identifier has multiple occurences, the position of the sub-expression is returned
3314 % where all occurences of it are located.
3315 % If the identifier is not found, the call fails.
3316 % Sub-expressions are meant like the ones syntaxtraversion or syntaxtransformation return.
3317 identifier_sub_ast(TExpr,Identifier,SubPosition) :-
3318 syntaxtraversion(TExpr,Expr,_Type,_Infos,AllSubs,Names),
3319 identifier_sub_ast_aux(Expr,AllSubs,Names,Identifier,SubPosition).
3320 identifier_sub_ast_aux(identifier(Identifier),[],[],Identifier,[]) :- !.
3321 identifier_sub_ast_aux(_Expr,AllSubs,Names,Identifier,SubPosition) :-
3322 get_texpr_id(TId,Identifier),nonmember(TId,Names),
3323 % For each sub-expression E in the list AllSubs create a term Pos-E
3324 % where Pos is E's position (starting with 0) in AllSubs
3325 foldl(annotate_pos,AllSubs,AllAnnotatedSubs,0,_),
3326 % Introduced identifiers occur alsa as sub-expressions, remove those
3327 foldl(select_sub,Names,AllAnnotatedSubs,RealAnnSubs),
3328 convlist_max(identifier_sub_ast_aux2(Identifier),2,RealAnnSubs,SubPositions), % find at most 2 sols
3329 ( SubPositions = [SubPosition] -> true
3330 ; SubPositions = [_,_|_] -> % More then one occurrences - make this the found node
3331 SubPosition = []).
3332 identifier_sub_ast_aux2(Identifier,Pos-TExpr,[Pos|SubPosition]) :-
3333 identifier_sub_ast(TExpr,Identifier,SubPosition).
3334 annotate_pos(TExpr,I-TExpr,I,I2) :- I2 is I+1.
3335 select_sub(Name,AnnotatedSubs,Result) :-
3336 selectchk(_Pos-Name,AnnotatedSubs,Result).
3337
3338
3339
3340 % exchange_ast_position(+SubPosition,+OldTExpr,-OldInner,+NewInner,-NewTExpr):
3341 % exchanges a sub-expression in the expression "OldTExpr".
3342 % SubPosition is a list of positions like identifier_sub_ast/3 returns it.
3343 % OldInner is the sub-expression found in OldTExpr.
3344 % NewInner is the new sub-expression.
3345 % NewTExpr is the new expression that originates from replacing OldInner by NewInner.
3346 exchange_ast_position([],Old,Old,New,New).
3347 exchange_ast_position([Pos|RestPos],OldTExpr,OldInner,NewInner,NewTExpr) :-
3348 remove_bt_and_used_ids(OldTExpr,OldExpr,NewExpr,NewTExpr), % also invalidates used_ids info
3349 ? syntaxtransformation(OldExpr,Subs,_Names,NSubs,NewExpr),
3350 nth0(Pos,Subs, OldSelected,Rest),
3351 nth0(Pos,NSubs,NewSelected,Rest),
3352 ? exchange_ast_position(RestPos,OldSelected,OldInner,NewInner,NewSelected).
3353
3354
3355 % -----------------------
3356 % utility to expand / inline all let expressions and let predicates:
3357 % useful for tools that cannot handle the lets
3358
3359 expand_all_lets(Expr,NewExpr) :-
3360 transform_bexpr(tl_expand_lets,Expr,NewExpr).
3361
3362 tl_expand_lets(b(E,_,_),Res) :- tl_expand_lets2(E,Res).
3363 tl_expand_lets2(let_expression(Ids,Exprs,Body),NewBody) :- % expand LET expression
3364 replace_ids_by_exprs(Body,Ids,Exprs,NewBody).
3365 tl_expand_lets2(let_predicate(Ids,Exprs,Body),NewBody) :- % expand LET predicate
3366 replace_ids_by_exprs(Body,Ids,Exprs,NewBody).
3367
3368 % -----------------------
3369
3370 :- public check_used_ids/2.
3371 % a simple checker, only checks used_ids info fields for entire typed expression:
3372 check_used_ids(TExpr,PP) :- %format('CHECK AST for ~w~n',[PP]),
3373 map_over_typed_bexpr(check_used_ids_texpr_fail(PP),TExpr).
3374 check_used_ids(_,_).
3375 check_used_ids_texpr_fail(PP,E) :- check_used_ids_texpr(PP,E),!,fail.
3376 check_used_ids_texpr(PP,b(P,T,I)) :- member(used_ids(UIds1),I),!,
3377 (find_identifier_uses(b(P,T,I),[],UIds2) -> true
3378 ; add_internal_error('find_identifier_uses failed',PP),fail),
3379 (UIds1==UIds2 -> true
3380 ; format('*** Wrong used_ids Info (~w)!!~n Used_ids: ~w~n Comp_ids: ~w~n',[PP,UIds1,UIds2]),
3381 translate:print_bexpr(b(P,T,I)),nl,
3382 add_error(check_used_ids,'Wrong used_ids: ',PP,I)
3383 ).
3384 check_used_ids_texpr(_,_).
3385
3386 % repair any broken used_ids info in typed expression TExpr and re-compute used_ids if necessary
3387 % PP is a program point, will be reported in case of an error
3388 repair_used_ids(PP,TExpr,Res) :-
3389 (transform_bexpr(bsyntaxtree:repair_used_ids_info(PP),TExpr,NewTExpr) -> Res=NewTExpr
3390 ; add_internal_error('Repairing used_ids failed:',PP),
3391 Res=TExpr).
3392
3393 % we could also simply call recompute_used_ids_inf; but it would not generate any messages
3394 repair_used_ids_info(PP,b(P,T,I),b(P,T,NI)) :- %functor(P,FF,_), print(repair(FF)),nl,
3395 ? select(used_ids(OldUsed),I,I2),!,
3396 (find_identifier_uses(b(P,T,I),[],NewUsed)
3397 -> (NewUsed=OldUsed -> NI=I
3398 ; NI = [used_ids(NewUsed)|I2],
3399 add_message(repair_used_ids,'Updating used_ids for: ',b(P,T,I),I2)
3400 )
3401 ; add_internal_error('find_identifier_uses failed',PP),
3402 NI=I
3403 ).
3404 repair_used_ids_info(PP,b(P,T,I),b(P,T,NI)) :-
3405 requires_used_ids(P),
3406 (find_identifier_uses(b(P,T,I),[],NewUsed) -> true
3407 ; add_internal_error('find_identifier_uses failed',PP),fail
3408 ),
3409 !,
3410 NI=[used_ids(NewUsed)|I].
3411 repair_used_ids_info(_,B,B).
3412
3413 requires_used_ids(exists(_,_)).
3414 requires_used_ids(forall(_,_,_)).
3415
3416 % a simple checker to see if an AST is well-formed:
3417 % can be tested e.g. as follows: b_get_invariant_from_machine(I), check_ast(I).
3418 % called in prob_safe_mode by clean_up_section
3419
3420 check_ast(TE) :- check_ast(false,TE).
3421 check_ast(AllowVars,TExpr) :- %nl,print('CHECK AST'),nl,
3422 map_over_typed_bexpr(check_ast_texpr(AllowVars),TExpr).
3423 check_ast(_,_).
3424
3425 :- use_module(typing_tools,[valid_ground_type/1]).
3426 %check_ast_texpr(X) :- print(check(X)),nl,fail.
3427 check_ast_texpr(AllowVars,AST) :- AST = b(E,Type,Infos),
3428 (debug:debug_level_active_for(9) -> write(' check_ast: '),print_bexpr(AST), write(' :: '), write(Type), nl ; true),
3429 (check_expr(E,Type,Infos) -> true
3430 ; add_error(check_ast_texpr,'Invalid Expr: ', AST) %, trace, check_expr(E,Type,Infos)
3431 ),
3432 (check_type(Type,AllowVars) -> true
3433 ; add_error(check_ast_texpr,'Invalid Type for: ',AST,Infos)),
3434 safe_functor(E,F),
3435 check_ast_typing(E,Type,Infos),
3436 (check_infos(Infos,F) -> true ; add_error(check_ast_texpr,'Invalid Infos: ',AST)),
3437 check_special_rules(E,Type,Infos),
3438 fail. % to force backtracking in map_over_typed_bexpr
3439
3440
3441 check_special_rules(operation_call_in_expr(Operation,_),_,OInfos) :- !,
3442 get_texpr_info(Operation,Info), % reads info important for used_ids computation
3443 (memberchk(reads(_V),Info) -> true
3444 ; add_error(check_ast_texpr,'Missing reads info: ',Operation,OInfos)).
3445
3446
3447 safe_functor(V,R) :- var(V),!,R='$VAR'.
3448 safe_functor(E,F/N) :- functor(E,F,N).
3449
3450 % check whether the type term is ok
3451 check_type(X,AllowVars) :- var(X),!,
3452 (AllowVars==true -> true ; add_error(check_type,'Variable type: ',X),fail).
3453 check_type(pred,_) :- !.
3454 check_type(subst,_) :- !.
3455 check_type(op(Paras,Returns),AllowVars) :- !,
3456 maplist(check_normal_type(AllowVars),Paras),
3457 maplist(check_normal_type(AllowVars),Returns).
3458 check_type(T,AllowVars) :- check_normal_type(AllowVars,T).
3459
3460 check_normal_type(AllowVars,T) :-
3461 (AllowVars \== true -> valid_ground_type(T)
3462 ; ground(T) -> valid_ground_type(T)
3463 ; true). % TO DO: call valid_ground_type but pass AllowVars
3464
3465 :- use_module(probsrc(btypechecker), [lookup_type_for_expr/2, unify_types_werrors/4]).
3466 % check whether type is compatible with operators
3467 check_ast_typing(member(A,B),Type,Pos) :- !,
3468 get_texpr_type(B,TB), check_set_type(TB,member,Pos),
3469 check_type(Type,pred,member),
3470 get_texpr_type(A,TA),
3471 unify_types_werrors(set(TA),TB,Pos,member).
3472 check_ast_typing(not_equal(A,B),Type,Pos) :- !, check_ast_typing(equal(A,B),Type,Pos).
3473 check_ast_typing(equal(A,B),Type,Pos) :- !,
3474 get_texpr_type(B,TB),
3475 get_texpr_type(A,TA),
3476 unify_types_werrors(TA,TB,Pos,'='),
3477 (non_value_type(TA)
3478 -> add_error(check_ast_typing,'Binary predicate has to have values as arguments:',TA,Pos)
3479 ; Type=pred -> true
3480 ; add_error(check_ast_typing,'Illegal type for binary predicate:',Type,Pos)
3481 ).
3482 check_ast_typing(greater_equal(A,B),Type,_) :- !,
3483 get_texpr_type(A,TA),check_type(TA,integer,greater_equal),
3484 get_texpr_type(B,TB),check_type(TB,integer,greater_equal), check_type(Type,pred,member).
3485 check_ast_typing(Expr,Type,Pos) :-
3486 syntaxtransformation(Expr,Subs,Names,NSubs,NewExpr),
3487 check_names(Names,Pos),
3488 (lookup_type(NewExpr,T) -> true
3489 ; add_warning(check_ast_typing,'Unable to lookup type for: ',NewExpr),
3490 fail
3491 ),
3492 !,
3493 (unify_types_werrors(Type,T,Pos,'check_ast')
3494 -> maplist(check_sub_type(Expr,Pos),Subs,NSubs)
3495 ; add_error(check_ast_typing,'Type mismatch for expression:',Expr,Pos)
3496 ).
3497 check_ast_typing(_,subst,_) :- !. % ignore subst for the moment
3498 check_ast_typing(operation(_TName,_Res,_Params,_TBody),_,_) :- !. % ignore operations for the moment
3499 check_ast_typing(Expr,_,Pos) :-
3500 syntaxtransformation(Expr,_,_Names,_,_NewExpr),!,
3501 add_message(check_ast_typing,'Cannot lookup type for expression: ',Expr,Pos).
3502 check_ast_typing(Expr,_,Pos) :-
3503 add_message(check_ast_typing,'No applicable type rule for expression: ',Expr,Pos).
3504
3505 non_value_type(X) :- var(X),!,fail.
3506 non_value_type(pred).
3507 non_value_type(subst).
3508 non_value_type(op(_)).
3509
3510
3511 check_names([],_).
3512 check_names([H|T],Pos) :-
3513 (member(H,T) -> add_error(check_ast_name,'Duplicate name:',H,Pos) ; check_names(T,Pos)).
3514
3515 check_sub_type(OuterExpr,Pos,Arg,Type) :- get_texpr_type(Arg,T),!,
3516 (unify_types_werrors(Type,T,Pos,'check_sub_type') -> true
3517 ; add_error(check_ast_typing,'Type mismatch for sub-expression:',Arg,Pos),
3518 write('Outer expression: '),translate:print_bexpr(OuterExpr),nl,
3519 write('Outer type: '),write(Type),nl,
3520 write('Arg type: '),write(T),nl,print(type(T)),nl, tools_printing:print_term_summary(Arg),nl,trace
3521 ).
3522 check_sub_type(_,Pos,Arg,_) :-
3523 add_error(check_ast_typing,'Cannot extract type: ',Arg,Pos).
3524
3525 lookup_type(identifier(_),_) :- !. % ignore typing issues for identifiers
3526 lookup_type(Expr,Type) :- lookup_type_for_expr(Expr,Type).
3527
3528 check_set_type(Var,_,_) :- var(Var),!.
3529 check_set_type(set(_),_,_) :- !.
3530 check_set_type(seq(_),_,_) :- !.
3531 check_set_type(Type,Func,Pos) :- add_error(check_ast_typing,'Invalid type for operator: ',Func:Type,Pos).
3532
3533 check_type(Type,Type,_) :- !.
3534 check_type(Type,_,Func) :- add_error(check_ast_typing,'Unexpected type for operator: ',Func:Type).
3535
3536 check_infos(X,F) :- var(X),!, add_error(check_infos,'Info field list not terminated: ',F:X),fail.
3537 check_infos([],_).
3538 check_infos([H|_],F) :- \+ ground(H),!, add_error(check_infos,'Info field not ground: ',F:H),fail.
3539 check_infos([[H|T]|_],F) :- !, add_error(check_infos,'Info field contains nested list: ',F:[H|T]),fail.
3540 check_infos([cse_used_ids(H)|T],F) :- member(cse_used_ids(H2),T),!,
3541 add_error(check_infos,'Multiple cse_used_ids entries: ',F:[H,H2]),fail.
3542 check_infos([used_ids(H)|T],F) :- member(used_ids(H2),T),!,
3543 add_error(check_infos,'Multiple used_ids entries: ',F:[H,H2]),fail.
3544 check_infos([nodeid(N1)|T],F) :- member(nodeid(N2),T),!,
3545 add_error(check_infos,'Multiple nodeid entries: ',F:[N1,N2],[nodeid(N1)]),fail.
3546 check_infos([removed_typing|T],F) :- member(removed_typing,T),!,
3547 add_error(check_infos,'Multiple removed_typing entries: ',F,T),fail.
3548 check_infos([_|T],F) :- check_infos(T,F).
3549
3550 check_expr(Expr,Type,Infos) :- nonmember(contains_wd_condition,Infos),
3551 sub_expression_contains_wd_condition(Expr,Sub),
3552 TE = b(Expr,Type,Infos),
3553 (Type = subst
3554 -> fail % AST cleanup is not called for substitutions; WD-info not available for substitutions at the moment
3555 ; translate_bexpression(TE,PS)),
3556 functor(Expr,Functor,_),
3557 functor(Sub,SubFunctor,_),
3558 tools:ajoin(['Node for AST node ',Functor,' does not contain WD info from Subexpression ',SubFunctor,' :'],Msg),
3559 add_warning(check_expr,Msg,PS,TE).
3560 % well_def_analyser:nested_print_wd_bexpr(TE),nl.
3561 % TODO: check when we have an unnecessary WD condition
3562 check_expr(Expr,Type,Infos) :- nonmember(contains_wd_condition,Infos),
3563 always_not_wd_top(Expr),
3564 add_warning(check_expr,'AST is not well-defined but does not contain WD info: ',b(Expr,Type,Infos),Infos).
3565 check_expr(member(LHS,RHS),Type,Infos) :- is_just_type(RHS),
3566 get_preference(optimize_ast,true),
3567 !,
3568 TE = b(member(LHS,RHS),Type,Infos),
3569 translate:translate_bexpression(TE,PS),
3570 add_warning(check_expr,'AST contains redundant typing predicate: ',PS,TE).
3571 check_expr(identifier(ID),_,_) :- illegal_id(ID),!,
3572 add_error(check_infos,'Illegal identifier: ', identifier(ID)).
3573 check_expr(lazy_lookup_expr(ID),_,_) :- illegal_id(ID),!,
3574 add_error(check_infos,'Illegal identifier: ', lazy_lookup_expr(ID)).
3575 check_expr(lazy_lookup_pred(ID),_,_) :- illegal_id(ID),!,
3576 add_error(check_infos,'Illegal identifier: ', lazy_lookup_pred(ID)).
3577 check_expr(exists(Parameters,Condition),pred,Infos) :- !,
3578 check_used_ids(exists,Parameters,Condition,Infos,_Used).
3579 check_expr(forall(Parameters,LHS,RHS),pred,Infos) :- !,
3580 create_implication(LHS,RHS,Condition),
3581 check_used_ids(forall,Parameters,Condition,Infos,_Used). %
3582 check_expr(value(V),Type,_) :- !, check_bvalue(V,Type).
3583 check_expr(_,_,_).
3584
3585 % will check all used_ids fields (not just for exists and forall)
3586 :- public check_used_ids_in_ast/1.
3587 check_used_ids_in_ast(closure(_,_,TExpr)) :- !, (map_over_typed_bexpr(check_used_ids_aux,TExpr) ; true).
3588 check_used_ids_in_ast(TExpr) :- map_over_typed_bexpr(check_used_ids_aux,TExpr).
3589 check_used_ids_in_ast(_).
3590
3591 check_used_ids_aux(AST) :- AST = b(_,_,Infos),
3592 ? member(used_ids(_),Infos),!,
3593 find_identifier_uses_if_necessary(AST,[],_), % will perform check
3594 fail.
3595
3596 % --------------------
3597
3598 :- use_module(specfile,[eventb_mode/0, z_or_tla_minor_mode/0]).
3599 % check if an expression is definitely not WD; looking at the top-level operator only
3600 always_not_wd_top(function(X,_)) :- definitely_empty_set(X). % TODO: detect a few more cases, e.g., arg not in dom
3601 always_not_wd_top(power_of(X,Y)) :- (get_integer(Y,VY), VY < 0 -> true
3602 ; eventb_mode, get_integer(X,VX), VX < 0).
3603 always_not_wd_top(div(_,Val)) :- get_integer(Val,VV), VV==0.
3604 always_not_wd_top(modulo(X,Y)) :-
3605 (get_integer(Y,VY), VY=<0
3606 -> true % there seems to be a def for Z in Z Live, cf modulo2
3607 ; get_integer(X,VX), VX<0, \+ z_or_tla_minor_mode).
3608 always_not_wd_top(min(X)) :- definitely_empty_set(X).
3609 always_not_wd_top(max(X)) :- definitely_empty_set(X).
3610 always_not_wd_top(size(X)) :- definitely_not_sequence(X). % TODO: detect infinite sets; also for card(_)
3611 always_not_wd_top(first(X)) :- definitely_not_non_empty_sequence(X).
3612 always_not_wd_top(front(X)) :- definitely_not_non_empty_sequence(X).
3613 always_not_wd_top(last(X)) :- definitely_not_non_empty_sequence(X).
3614 always_not_wd_top(tail(X)) :- definitely_not_non_empty_sequence(X).
3615 always_not_wd_top(general_intersection(X)) :- definitely_empty_set(X).
3616
3617 definitely_not_non_empty_sequence(X) :-
3618 (definitely_empty_set(X) -> true ; definitely_not_sequence(X)).
3619
3620 :- use_module(avl_tools,[avl_min_pair/3]).
3621 definitely_not_sequence(b(value(A),_,_)) :- nonvar(A), A=avl_set(AVL),
3622 avl_min_pair(AVL,int(StartIndex),_), StartIndex \= 1.
3623 % TODO: treat set_extension
3624
3625 :- use_module(b_ast_cleanup,[check_used_ids_info/4]).
3626 check_used_ids(Quantifier,Parameters,Condition,Infos,Used) :-
3627 ? select(used_ids(Used),Infos,Rest)
3628 -> check_used_ids_info(Parameters,Condition,Used,Quantifier), %% comment in to check used_ids field
3629 (member(used_ids(_),Rest)
3630 -> add_internal_error('Multiple used_ids info fields:',Parameters:Infos) ; true)
3631 ;
3632 add_internal_error(
3633 'Expected information of used identifiers information',Quantifier:Parameters:Infos).
3634
3635 illegal_id(ID) :- var(ID),!.
3636 illegal_id(op(ID)) :- !, \+ atom(ID).
3637 illegal_id(ID) :- \+ atom(ID).
3638
3639 :- use_module(btypechecker, [unify_types_strict/2, couplise_list/2]).
3640 :- use_module(avl_tools,[check_is_non_empty_avl/1]).
3641 % TO DO: we could check type more
3642 check_bvalue(V,_) :- var(V),!.
3643 check_bvalue(avl_set(A),Type) :- !, unify_types_strict(Type,set(_)),
3644 check_is_non_empty_avl(A).
3645 check_bvalue(closure(_,T,B),Type) :- !,
3646 couplise_list(T,CT), unify_types_strict(set(CT),Type),
3647 check_ast(B).
3648 check_bvalue(_,_).
3649
3650 % -----------------------
3651
3652
3653 indent_ws(X) :- X<1,!.
3654 indent_ws(X) :- print(' '), X1 is X-1, indent_ws(X1).
3655
3656 print_ast_td(b(E,T,I),Level,L1) :-
3657 indent_ws(Level),
3658 (E=identifier(_)
3659 -> format('~w (~w) -> ~w~n',[E,T,I])
3660 ; functor(E,F,N),
3661 format('~w/~w (~w) -> ~w~n',[F,N,T,I])
3662 ),
3663 L1 is Level+1.
3664 print_ast(TExpr) :-
3665 (map_over_typed_bexpr_top_down_acc(print_ast_td,TExpr,0),fail ; true).
3666
3667 % ---------------------
3668
3669 :- dynamic count_id_usage/2.
3670 single_usage_id_count(Expr) :- uses_an_identifier(Expr,Id),
3671 retract(count_id_usage(Id,Count)),
3672 !,
3673 Count=0,
3674 C1 is Count+1,
3675 assertz(count_id_usage(Id,C1)).
3676 single_usage_id_count(_).
3677
3678 % check if an identifier is used at most once
3679 single_usage_identifier(ID,ExprOrPredicates,Count) :-
3680 retractall(count_id_usage(_,_)),
3681 assertz(count_id_usage(ID,0)),
3682 % TO DO: take care of naming; do not count occurences when we enter scope defining ID
3683 maplist(single_usage_cnt,ExprOrPredicates),
3684 retract(count_id_usage(ID,Count)).
3685
3686 single_usage_cnt(ExprOrPredicate) :- map_over_full_bexpr_no_fail(single_usage_id_count,ExprOrPredicate).
3687
3688 gen_fresh_id_if_necessary(Default,Expr,FreshID) :-
3689 occurs_in_expr(Default,Expr),!,
3690 gensym('__FRESH_ID__',FreshID). % assumes _Fresh_XXX not used
3691 gen_fresh_id_if_necessary(Default,_,Default).
3692
3693 %% rewrite_if_then_else_expr_to_b(IfThenElseExpr, NExpr).
3694 % Rewrite if-then-else expr to B as understood by Atelier-B.
3695 % {d,x| d:BOOL & If => x=Then & not(if) => x=Else}(TRUE)
3696 rewrite_if_then_else_expr_to_b(if_then_else(If,Then,Else), NExpr) :-
3697 get_texpr_type(Then,Type),
3698 ARG = b(boolean_true,boolean,[]), AT=boolean, % we could use unit type or BOOL here
3699 gen_fresh_id_if_necessary('_zzzz_unary',b(if_then_else(If,Then,Else),Type,[]),AID1),
3700 gen_fresh_id_if_necessary('_zzzz_binary',b(if_then_else(If,Then,Else),Type,[]),AID2),
3701 safe_create_texpr(identifier(AID1), AT, [], Id1), % a dummy argument
3702 safe_create_texpr(identifier(AID2), Type, [], Id2), % The result
3703 safe_create_texpr(equal(Id2,Then), pred, [], Eq1),
3704 safe_create_texpr(equal(Id2,Else), pred, [], Eq2),
3705 safe_create_texpr(implication(If,Eq1), pred, [], Pred1),
3706 safe_create_texpr(negation(If), pred, [], NIf),
3707 safe_create_texpr(implication(NIf,Eq2), pred, [], Pred2),
3708 safe_create_texpr(conjunct(Pred1,Pred2), pred, [], Pred),
3709 safe_create_texpr(comprehension_set([Id1,Id2],Pred), set(couple(AT,Type)), [], FUN),
3710 NExpr = function(FUN,ARG).
3711
3712
3713 % --------------------
3714
3715 % apply normalisation rules from Atlier-B PP/ML provers
3716 % see chapter 3 of Atelier-B prover manual
3717
3718 normalise_bexpr_for_ml(TExpr,Res) :-
3719 transform_bexpr(normalise_bexpr,TExpr,Res).
3720
3721 normalise_bexpr(b(E,T,I),b(E2,T,I)) :- norm2(E,E2),!.
3722
3723 norm2(equivalence(A,B),conjunct(TIMP1,TIMP2)) :- !,
3724 safe_create_texpr(implication(A,B),pred,TIMP1),
3725 safe_create_texpr(implication(B,A),pred,TIMP2).
3726 norm2(subset_strict(A,B),conjunct(TMEM,TNEQ)) :- !,
3727 norm2(subset(A,B),MEM), safe_create_texpr(MEM,pred,TMEM),
3728 safe_create_not_equal(A,B,TNEQ).
3729 norm2(subset(A,B),member(A,PowB)) :- !, % A <: B <===> A:POW(B)
3730 get_texpr_type(A,TA),
3731 safe_create_texpr(pow_subset(B),TA,PowB).
3732 norm2(not_equal(A,B),negation(TEQ)) :- !,
3733 safe_create_texpr(equal(A,B),pred,TEQ).
3734 norm2(not_member(A,B),negation(TMEM)) :- !,
3735 safe_create_texpr(member(A,B),pred,TMEM).
3736 norm2(not_subset(A,B),negation(TMEM)) :- !,
3737 norm2(subset(A,B),MEM),safe_create_texpr(MEM,pred,TMEM).
3738 norm2(not_subset_strict(A,B),implication(TMEM,TEQ)) :- !, % A /<< : B <===> A:POW(B) => A=B
3739 norm2(subset(A,B),MEM),safe_create_texpr(MEM,pred,TMEM),
3740 safe_create_texpr(equal(A,B),pred,TEQ).
3741 norm2(POW1,set_subtraction(TPOW,TSEMPTY)) :- not_empty_pow(POW1,A,POW), !,
3742 % POW1(A) <===> POW(A) - {{}}, FIN1(A) <===> FIN(A) - {{}}, ...
3743 safe_create_texpr(POW,pred,TPOW),
3744 get_texpr_type(A,TA), TEMPTY = b(empty_set,TA,[]),
3745 safe_create_texpr(set_extension([TEMPTY]),set(TA),TSEMPTY).
3746 norm2(member(A,b(integer_set('NATURAL'),_,_)),conjunct(TMEM,TLEQ)) :- !, % A <: NATURAL <===> A:INTEGER & 0 <= A
3747 INTEGER = b(integer_set('INTEGER'),set(integer),[]),
3748 safe_create_texpr(member(A,INTEGER),pred,TMEM),
3749 Zero = b(integer(0),integer,[]),
3750 safe_create_texpr(less_equal(Zero,A),pred,TLEQ).
3751 norm2(set_extension(List),Union) :- List = [H|T], T=[_|_], !, % {A,B} <===> {A} \/ {B}
3752 get_texpr_type(H,Type),
3753 set_extension_to_union(H,T,set(Type),b(Union,_,_)).
3754 norm2(greater_equal(A,B),less_equal(B,A)) :- !.
3755 norm2(greater(A,B),less_equal(B1,A)) :- !, plus1(B,B1).
3756 norm2(less(A,B),less_equal(A,B1)) :- !, minus1(B,B1). % the normalisation rule in chapter 3 is actually false
3757 norm2(integer_set(NAT1),set_subtraction(TNAT,TSZero)) :- nat1(NAT1,NAT), !, % NATURAL1 <===> NATURAL - {0}
3758 TNAT = b(integer_set(NAT),set(integer),[]),
3759 set_with_zero(TSZero).
3760 norm2(empty_sequence,empty_set) :- !.
3761 norm2(perm(A),intersection(ISEQ,PSURJ)) :- !, % perm(A) <===> iseq(A) /\ (NATURAL-{0} +->> A)
3762 get_texpr_type(A,TA),
3763 safe_create_texpr(iseq(A),set(seq(TA)),ISEQ),
3764 set_with_zero(TSZero),
3765 NATURAL = b(integer_set('NATURAL'),set(integer),[]),
3766 safe_create_texpr(set_subtraction(NATURAL,TSZero),set(integer),DOM),
3767 safe_create_texpr(partial_surjection(DOM,A),set(seq(TA)),PSURJ).
3768 % TODO: total_relation, if_then_else, ...?
3769
3770 set_with_zero(TSZero) :- % {0}
3771 TZero = b(integer(0),TA,[]),
3772 safe_create_texpr(set_extension([TZero]),set(TA),TSZero).
3773
3774 % TODO: more intelligent versions like x-1 ==> x ...
3775 plus1(A,Plus1) :- One = b(integer(1),integer,[]),
3776 safe_create_texpr(add(A,One),integer,Plus1).
3777 minus1(A,Plus1) :- One = b(integer(1),integer,[]),
3778 safe_create_texpr(minus(A,One),integer,Plus1).
3779
3780 not_empty_pow(pow1_subset(A),A,pow_subset(A)).
3781 not_empty_pow(fin1_subset(A),A,fin_subset(A)).
3782 not_empty_pow(seq1(A),A,seq(A)).
3783 not_empty_pow(iseq1(A),A,iseq(A)).
3784
3785 nat1('NATURAL1','NATURAL').
3786 nat1('NAT1','NAT').
3787
3788 safe_create_not_equal(A,B,TNEQ) :-
3789 safe_create_texpr(equal(A,B),pred,TEQ),
3790 safe_create_texpr(negation(TEQ),pred,TNEQ).
3791
3792 set_extension_to_union(H,[],Type,Res) :- !,
3793 safe_create_texpr(set_extension([H]),Type,Res).
3794 set_extension_to_union(H,[H2|T],Type,Res) :-
3795 safe_create_texpr(set_extension([H]),Type,TH),
3796 set_extension_to_union(H2,T,Type,TUnion),
3797 safe_create_texpr(union(TH,TUnion),Type,Res).