2 ||M|| This file is part of HELM, an Hypertextual, Electronic
3 ||A|| Library of Mathematics, developed at the Computer Science
4 ||T|| Department, University of Bologna, Italy.
6 ||T|| HELM is free software; you can redistribute it and/or
7 ||A|| modify it under the terms of the GNU General Public License
8 \ / version 2 or (at your option) any later version.
9 \ / This software is distributed as is, NO WARRANTY.
10 V_______________________________________________________________ *)
12 (* $Id: index.mli 9822 2009-06-03 15:37:06Z tassi $ *)
14 module Superposition (B : Orderings.Blob) =
16 module IDX = Index.Index(B)
17 module Unif = FoUnif.Founif(B)
18 module Subst = FoSubst
20 module Utils = FoUtils.Utils(B)
23 exception Success of B.t Terms.bag * int * B.t Terms.clause
25 let debug s = prerr_endline (Lazy.force s);;
29 let rec list_first f = function
31 | x::tl -> match f x with Some _ as x -> x | _ -> list_first f tl
34 let first_position pos ctx t f =
35 let inject_pos pos ctx = function
37 | Some (a,b,c,d) -> Some(ctx a,b,c,d,pos)
39 let rec aux pos ctx = function
40 | Terms.Leaf _ as t -> inject_pos pos ctx (f t)
44 | Some _ as x -> inject_pos pos ctx x
46 let rec first pre post = function
49 let newctx = fun x -> ctx (Terms.Node (pre@[x]@post)) in
50 match aux (List.length pre :: pos) newctx t with
53 if post = [] then None (* tl is also empty *)
54 else first (pre @ [t]) (List.tl post) tl
56 first [] (List.tl l) l
61 let all_positions pos ctx t f =
62 let rec aux pos ctx = function
63 | Terms.Leaf _ as t -> f t pos ctx
68 (fun (acc,pre,post) t -> (* Invariant: pre @ [t] @ post = l *)
69 let newctx = fun x -> ctx (Terms.Node (pre@[x]@post)) in
70 let acc = aux (List.length pre :: pos) newctx t @ acc in
71 if post = [] then acc, l, []
72 else acc, pre @ [t], List.tl post)
73 (f t pos ctx, [], List.tl l) l
80 let parallel_positions bag pos ctx id t f =
81 let rec aux bag pos ctx id = function
82 | Terms.Leaf _ as t -> f bag t pos ctx id
83 | Terms.Var _ as t -> bag,t,id
84 | Terms.Node (hd::l) as t->
85 let bag,t,id1 = f bag t pos ctx id in
89 (fun (bag,pre,post,id) t ->
90 let newctx = fun x -> ctx (Terms.Node (pre@[x]@post)) in
91 let newpos = (List.length pre)::pos in
92 let bag,newt,id = aux bag newpos newctx id t in
93 if post = [] then bag, pre@[newt], [], id
94 else bag, pre @ [newt], List.tl post, id)
95 (bag, [hd], List.tl l, id) l
104 let build_clause bag filter rule t subst id id2 pos dir =
105 let proof = Terms.Step(rule,id,id2,dir,pos,subst) in
106 let t = Subst.apply_subst subst t in
110 | Terms.Node [ Terms.Leaf eq ; ty; l; r ] when B.eq B.eqP eq ->
111 let o = Order.compare_terms l r in
112 Terms.Equation (l, r, ty, o)
113 | t -> Terms.Predicate t
116 Terms.add_to_bag (0, [], [literal,true], Terms.vars_of_term t, proof) bag
120 ((*prerr_endline ("Filtering: " ^ Pp.pp_foterm t);*)None)
122 let prof_build_clause = HExtlib.profile ~enable "build_clause";;
123 let build_clause bag filter rule t subst id id2 pos x =
124 prof_build_clause.HExtlib.profile (build_clause bag filter rule t subst id id2 pos) x
128 (* ============ simplification ================= *)
129 let prof_demod_u = HExtlib.profile ~enable "demod.unify";;
130 let prof_demod_r = HExtlib.profile ~enable "demod.retrieve_generalizations";;
131 let prof_demod_o = HExtlib.profile ~enable "demod.compare_terms";;
132 let prof_demod_s = HExtlib.profile ~enable "demod.apply_subst";;
134 let demod table varlist subterm =
136 prof_demod_r.HExtlib.profile
137 (IDX.DT.retrieve_generalizations table) subterm
140 (fun (dir, is_pos, pos, (id,nlit,plit,vl,_)) ->
144 | Terms.Predicate _ -> assert false
145 | Terms.Equation (l,r,_,o) ->
146 let side, newside = if dir=Terms.Left2Right then l,r else r,l in
149 prof_demod_u.HExtlib.profile
150 (Unif.unification (* (varlist@vl) *) varlist subterm) side
153 prof_demod_s.HExtlib.profile
154 (Subst.apply_subst subst) side
157 prof_demod_s.HExtlib.profile
158 (Subst.apply_subst subst) newside
160 if o = Terms.Incomparable || o = Terms.Invertible then
162 prof_demod_o.HExtlib.profile
163 (Order.compare_terms newside) side in
164 (* Riazanov, pp. 45 (ii) *)
166 Some (newside, subst, id, dir)
168 ((*prerr_endline ("Filtering: " ^
169 Pp.pp_foterm side ^ " =(< || =)" ^
170 Pp.pp_foterm newside ^ " coming from " ^
171 Pp.pp_clause uc );*)None)
173 Some (newside, subst, id, dir)
174 with FoUnif.UnificationFailure _ -> None)
176 (IDX.ClauseSet.elements cands)
178 let prof_demod = HExtlib.profile ~enable "demod";;
179 let demod table varlist x =
180 prof_demod.HExtlib.profile (demod table varlist) x
183 let parallel_demod table vl bag t pos ctx id =
184 match demod table vl t with
186 | Some (newside, subst, id2, dir) ->
187 match build_clause bag (fun _ -> true)
188 Terms.Demodulation (ctx newside) subst id id2 pos dir
190 | None -> assert false
191 | Some (bag,(id,_,_,_,_)) ->
195 let demodulate_once ~jump_to_right bag (id, nlit, plit, vl, pr) table =
199 | Terms.Predicate t -> assert false
200 | Terms.Equation (l,r,ty,_) ->
201 let bag,l,id1 = if jump_to_right then (bag,l,id) else
202 parallel_positions bag [2]
203 (fun x -> Terms.Node [ Terms.Leaf B.eqP; ty; x; r ]) id l
204 (parallel_demod table vl)
206 let jump_to_right = id1 = id in
208 parallel_positions bag [3]
209 (fun x -> Terms.Node [ Terms.Leaf B.eqP; ty; l; x ]) id1 r
210 (parallel_demod table vl)
212 if id = id2 then None
214 let cl,_,_ = Terms.get_from_bag id2 bag in
215 Some ((bag,cl),jump_to_right))
219 let rec demodulate ~jump_to_right bag clause table =
220 match demodulate_once ~jump_to_right bag clause table with
221 | None -> bag, clause
222 | Some ((bag, clause),r) -> demodulate ~jump_to_right:r
226 let are_alpha_eq cl1 cl2 =
227 let get_term (_,nlit,plit,_,_) =
229 | [], [Terms.Equation (l,r,ty,_),_] ->
230 Terms.Node [Terms.Leaf B.eqP; ty; l ; r]
233 try ignore(Unif.alpha_eq (get_term cl1) (get_term cl2)) ; true
234 with FoUnif.UnificationFailure _ -> false
237 let demodulate bag clause table =
238 (* let (bag1,c1), (_,c2) =*)
239 demodulate ~jump_to_right:false bag clause table
240 (* demodulate_old ~jump_to_right:false bag clause table *)
242 if are_alpha_eq c1 c2 then bag1,c1
244 prerr_endline (Pp.pp_clause c1);
245 prerr_endline (Pp.pp_clause c2);
246 prerr_endline "Bag :";
247 prerr_endline (Pp.pp_bag bag1);
251 let prof_demodulate = HExtlib.profile ~enable "demodulate";;
252 let demodulate bag clause x =
253 prof_demodulate.HExtlib.profile (demodulate bag clause) x
257 let is_identity_clause ~unify = function
258 | _, [], [Terms.Equation (_,_,_,Terms.Eq),_], _, _ -> true
259 | _, [], [Terms.Equation (l,r,_,_),_], vl, proof when unify ->
260 (try ignore(Unif.unification (* vl *) [] l r); true
261 with FoUnif.UnificationFailure _ -> false)
262 | _, [], [Terms.Equation (_,_,_,_),_], _, _ -> false
266 let build_new_clause bag maxvar filter rule t subst id id2 pos dir =
267 let maxvar, _vl, subst = Utils.relocate maxvar (Terms.vars_of_term
268 (Subst.apply_subst subst t)) subst in
269 match build_clause bag filter rule t subst id id2 pos dir with
270 | Some (bag, c) -> Some ((bag, maxvar), c)
273 let prof_build_new_clause = HExtlib.profile ~enable "build_new_clause";;
274 let build_new_clause bag maxvar filter rule t subst id id2 pos x =
275 prof_build_new_clause.HExtlib.profile (build_new_clause bag maxvar filter
276 rule t subst id id2 pos) x
279 let fold_build_new_clause bag maxvar id rule filter res =
280 let (bag, maxvar), res =
281 HExtlib.filter_map_acc
282 (fun (bag, maxvar) (t,subst,id2,pos,dir) ->
283 build_new_clause bag maxvar filter rule t subst id id2 pos dir)
289 (* Tries to rewrite an equality to identity, using unit equalities in table *)
290 let rewrite_eq ~unify l r ty vl table =
291 let retrieve = if unify then IDX.DT.retrieve_unifiables
292 else IDX.DT.retrieve_generalizations in
293 let lcands = retrieve table l in
294 let rcands = retrieve table r in
296 let id, dir, l, r, vl =
298 | (d,_,_, (id,[],[Terms.Equation (l,r,ty,_),_],vl,_))-> id, d, l, r, vl
301 let reverse = (dir = Terms.Left2Right) = b in
302 let l, r, proof_rewrite_dir = if reverse then l,r,Terms.Left2Right
303 else r,l, Terms.Right2Left in
304 (id,proof_rewrite_dir,Terms.Node [ Terms.Leaf B.eqP; ty; l; r ], vl)
306 let cands1 = List.map (f true) (IDX.ClauseSet.elements lcands) in
307 let cands2 = List.map (f false) (IDX.ClauseSet.elements rcands) in
308 let t = Terms.Node [ Terms.Leaf B.eqP; ty; l; r ] in
309 let locked_vars = if unify then [] else vl in
310 let rec aux = function
312 | (id2,dir,c,vl1)::tl ->
314 let subst = Unif.unification (* (vl@vl1) *) locked_vars c t in
315 Some (id2, dir, subst)
316 with FoUnif.UnificationFailure _ -> aux tl
318 aux (cands1 @ cands2)
321 let is_subsumed ~unify bag maxvar (id, nlit, plit, vl, _) table =
323 | [],[Terms.Equation (l,r,ty,_) ,_]->
324 (match rewrite_eq ~unify l r ty vl table with
326 | Some (id2, dir, subst) ->
327 let id_t = Terms.Node [ Terms.Leaf B.eqP; ty; r; r ] in
328 build_new_clause bag maxvar (fun _ -> true)
329 Terms.Superposition id_t subst id id2 [2] dir)
332 let prof_is_subsumed = HExtlib.profile ~enable "is_subsumed";;
333 let is_subsumed ~unify bag maxvar c x =
334 prof_is_subsumed.HExtlib.profile (is_subsumed ~unify bag maxvar c) x
336 (* id refers to a clause proving contextl l = contextr r *)
338 let rec deep_eq ~unify l r ty pos contextl contextr table acc =
341 | Some(bag,maxvar,(id,nlit,plit,vl,p),subst) ->
342 let l = Subst.apply_subst subst l in
343 let r = Subst.apply_subst subst r in
345 let subst1 = Unif.unification (* vl *) [] l r in
348 | [],[Terms.Equation (l,r,ty,o),_] ->
349 Terms.Equation (FoSubst.apply_subst subst1 l,
350 FoSubst.apply_subst subst1 r, ty, o)
353 Some(bag,maxvar,(id,[],[lit,true],vl,p),Subst.concat subst1 subst)
354 with FoUnif.UnificationFailure _ ->
355 match rewrite_eq ~unify l r ty vl table with
356 | Some (id2, dir, subst1) ->
357 let newsubst = Subst.concat subst1 subst in
359 FoSubst.apply_subst newsubst
360 (Terms.Node[Terms.Leaf B.eqP;ty;contextl r;contextr r])
363 build_new_clause bag maxvar (fun _ -> true)
364 Terms.Superposition id_t
365 subst1 id id2 (pos@[2]) dir
367 | Some ((bag, maxvar), c) ->
368 Some(bag,maxvar,c,newsubst)
369 | None -> assert false)
372 | Terms.Node (a::la), Terms.Node (b::lb) when
373 a = b && List.length la = List.length lb ->
376 (fun (acc,pre,postl,postr) a b ->
378 fun x -> contextl(Terms.Node (pre@(x::postl))) in
380 fun x -> contextr(Terms.Node (pre@(x::postr))) in
381 let newpos = List.length pre::pos in
383 if l = [] then [] else List.tl l in
384 (deep_eq ~unify a b ty
385 newpos newcl newcr table acc,pre@[b],
386 footail postl, footail postr))
387 (acc,[a],List.tl la,List.tl lb) la lb
391 let prof_deep_eq = HExtlib.profile ~enable "deep_eq";;
392 let deep_eq ~unify l r ty pos contextl contextr table x =
393 prof_deep_eq.HExtlib.profile (deep_eq ~unify l r ty pos contextl contextr table) x
396 let rec orphan_murder bag acc i =
397 match Terms.get_from_bag i bag with
398 | (_,_,_,_,Terms.Exact _),discarded,_ -> (discarded,acc)
399 | (_,_,_,_,Terms.Step (_,i1,i2,_,_,_)),true,_ -> (true,acc)
400 | (_,_,_,_,Terms.Step (_,i1,i2,_,_,_)),false,_ ->
401 if (List.mem i acc) then (false,acc)
402 else match orphan_murder bag acc i1 with
403 | (true,acc) -> (true,acc)
405 let (res,acc) = orphan_murder bag acc i2 in
406 if res then res,acc else res,i::acc
409 let orphan_murder bag actives cl =
410 let (id,_,_,_,_) = cl in
411 let actives = List.map (fun (i,_,_,_,_) -> i) actives in
412 let (res,_) = orphan_murder bag actives id in
413 if res then debug (lazy "Orphan murdered"); res
415 let prof_orphan_murder = HExtlib.profile ~enable "orphan_murder";;
416 let orphan_murder bag actives x =
417 prof_orphan_murder.HExtlib.profile (orphan_murder bag actives) x
420 (* demodulate and check for subsumption *)
421 let simplify table maxvar bag clause =
422 if is_identity_clause ~unify:false clause then bag,None
423 (* else if orphan_murder bag actives clause then bag,None *)
424 else let bag, clause = demodulate bag clause table in
425 if is_identity_clause ~unify:false clause then bag,None
427 match is_subsumed ~unify:false bag maxvar clause table with
428 | None -> bag, Some clause
429 | Some _ -> bag, None
432 let simplify table maxvar bag clause =
433 match simplify table maxvar bag clause with
435 let (id,_,_,_,_) = clause in
436 let (_,_,iter) = Terms.get_from_bag id bag in
437 Terms.replace_in_bag (clause,true,iter) bag, None
438 | bag, Some clause -> bag, Some clause
439 (*let (id,_,_,_) = clause in
440 if orphan_murder bag clause then
441 Terms.M.add id (clause,true) bag, Some clause
442 else bag, Some clause*)
444 let prof_simplify = HExtlib.profile ~enable "simplify";;
445 let simplify table maxvar bag x =
446 prof_simplify.HExtlib.profile (simplify table maxvar bag ) x
449 let one_pass_simplification new_clause (alist,atable) bag maxvar =
450 match simplify atable maxvar bag new_clause with
451 | bag,None -> bag,None (* new_clause has been discarded *)
452 | bag,(Some clause) ->
453 let ctable = IDX.index_clause IDX.DT.empty clause in
454 let bag, alist, atable =
456 (fun (bag, alist, atable) c ->
457 match simplify ctable maxvar bag c with
458 |bag,None -> (bag,alist,atable)
459 (* an active clause as been discarded *)
461 bag, c :: alist, IDX.index_clause atable c)
462 (bag,[],IDX.DT.empty) alist
464 bag, Some (clause, (alist,atable))
466 let prof_one_pass_simplification = HExtlib.profile ~enable "one_pass_simplification";;
467 let one_pass_simplification new_clause t bag x =
468 prof_one_pass_simplification.HExtlib.profile (one_pass_simplification new_clause t bag ) x
471 let simplification_step ~new_cl cl (alist,atable) bag maxvar new_clause =
473 if new_cl then atable else
474 IDX.index_clause atable cl
476 (* Simplification of new_clause with : *
477 * - actives and cl if new_clause is not cl *
478 * - only actives otherwise *)
480 simplify atable1 maxvar bag new_clause with
481 | bag,None -> bag,(Some cl, None) (* new_clause has been discarded *)
483 (* Simplification of each active clause with clause *
484 * which is the simplified form of new_clause *)
485 let ctable = IDX.index_clause IDX.DT.empty clause in
486 let bag, newa, alist, atable =
488 (fun (bag, newa, alist, atable) c ->
489 match simplify ctable maxvar bag c with
490 |bag,None -> (bag, newa, alist, atable)
491 (* an active clause as been discarded *)
494 bag, newa, c :: alist,
495 IDX.index_clause atable c
497 bag, c1 :: newa, alist, atable)
498 (bag,[],[],IDX.DT.empty) alist
501 bag, (Some cl, Some (clause, (alist,atable), newa))
503 (* if new_clause is not cl, we simplify cl with clause *)
504 match simplify ctable maxvar bag cl with
506 (* cl has been discarded *)
507 bag,(None, Some (clause, (alist,atable), newa))
509 bag,(Some cl1, Some (clause, (alist,atable), newa))
511 let prof_simplification_step = HExtlib.profile ~enable "simplification_step";;
512 let simplification_step ~new_cl cl (alist,atable) bag maxvar x =
513 prof_simplification_step.HExtlib.profile (simplification_step ~new_cl cl (alist,atable) bag maxvar) x
516 let keep_simplified cl (alist,atable) bag maxvar =
517 let rec keep_simplified_aux ~new_cl cl (alist,atable) bag newc =
519 match simplification_step ~new_cl cl (alist,atable) bag maxvar cl with
520 | _,(None, _) -> assert false
521 | bag,(Some _, None) -> bag,None
522 | bag,(Some _, Some (clause, (alist,atable), newa)) ->
523 keep_simplified_aux ~new_cl:(cl!=clause) clause (alist,atable)
527 | [] -> bag, Some (cl, (alist,atable))
529 match simplification_step ~new_cl cl
530 (alist,atable) bag maxvar hd with
531 | _,(None,None) -> assert false
532 | bag,(Some _,None) ->
533 keep_simplified_aux ~new_cl cl (alist,atable) bag tl
534 | bag,(None, Some _) -> bag,None
535 | bag,(Some cl1, Some (clause, (alist,atable), newa)) ->
537 (clause::alist, IDX.index_clause atable clause)
539 keep_simplified_aux ~new_cl:(cl!=cl1) cl1 (alist,atable)
542 keep_simplified_aux ~new_cl:true cl (alist,atable) bag []
544 let prof_keep_simplified = HExtlib.profile ~enable "keep_simplified";;
545 let keep_simplified cl t bag x =
546 prof_keep_simplified.HExtlib.profile (keep_simplified cl t bag) x
549 (* this is like simplify but raises Success *)
550 let simplify_goal ~no_demod maxvar table bag g_actives clause =
552 if no_demod then bag, clause else demodulate bag clause table
554 if List.exists (are_alpha_eq clause) g_actives then None else
555 if (is_identity_clause ~unify:true clause)
556 then raise (Success (bag, maxvar, clause))
558 let (id,nlit,plit,vl,_) = clause in
559 if vl = [] then Some (bag,clause)
563 | [],[Terms.Equation(l,r,ty,_),_] -> l,r,ty
566 match deep_eq ~unify:true l r ty [] (fun x -> x) (fun x -> x)
567 table (Some(bag,maxvar,clause,Subst.id_subst)) with
568 | None -> Some (bag,clause)
569 | Some (bag,maxvar,cl,subst) ->
570 prerr_endline "Goal subsumed";
571 raise (Success (bag,maxvar,cl))
573 else match is_subsumed ~unify:true bag maxvar clause table with
574 | None -> Some (bag, clause)
575 | Some ((bag,maxvar),c) ->
576 prerr_endline "Goal subsumed";
577 raise (Success (bag,maxvar,c))
581 let prof_simplify_goal = HExtlib.profile ~enable "simplify_goal";;
582 let simplify_goal ~no_demod maxvar table bag g_actives x =
583 prof_simplify_goal.HExtlib.profile ( simplify_goal ~no_demod maxvar table bag g_actives) x
586 (* =================== inference ===================== *)
588 (* this is OK for both the sup_left and sup_right inference steps *)
589 let superposition table varlist subterm pos context =
590 let cands = IDX.DT.retrieve_unifiables table subterm in
591 debug (lazy (string_of_int (IDX.ClauseSet.cardinal cands) ^ " candidates found"));
593 (fun (dir, _, _, (id,nlit,plit,vl,_ (*as uc*))) ->
595 | [],[Terms.Equation (l,r,_,o),_] ->
596 (let side, newside = if dir=Terms.Left2Right then l,r else r,l in
599 Unif.unification (* (varlist@vl)*) [] subterm side
601 if o = Terms.Incomparable || o = Terms.Invertible then
602 let side = Subst.apply_subst subst side in
603 let newside = Subst.apply_subst subst newside in
604 let o = Order.compare_terms side newside in
605 (* XXX: check Riazanov p. 33 (iii) *)
606 if o <> Terms.Lt && o <> Terms.Eq then
607 Some (context newside, subst, id, pos, dir)
609 ((*prerr_endline ("Filtering: " ^
610 Pp.pp_foterm side ^ " =(< || =)" ^
611 Pp.pp_foterm newside);*)None)
613 Some (context newside, subst, id, pos, dir)
614 with FoUnif.UnificationFailure _ -> None)
616 (IDX.ClauseSet.elements cands)
619 (* Superposes selected equation with equalities in table *)
620 let superposition_with_table bag maxvar (id,nlit,plit,vl,_) table =
622 | [],[Terms.Equation (l,r,ty,Terms.Lt),_] ->
623 fold_build_new_clause bag maxvar id Terms.Superposition
626 (fun x -> Terms.Node [ Terms.Leaf B.eqP; ty; l; x ])
627 r (superposition table vl))
628 | [],[Terms.Equation (l,r,ty,Terms.Invertible),_]
629 | [],[Terms.Equation (l,r,ty,Terms.Gt),_] ->
630 fold_build_new_clause bag maxvar id Terms.Superposition
633 (fun x -> Terms.Node [ Terms.Leaf B.eqP; ty; x; r ])
634 l (superposition table vl))
635 | [],[Terms.Equation (l,r,ty,Terms.Incomparable),_] ->
636 let filtering avoid subst = (* Riazanov: p.33 condition (iv) *)
637 let l = Subst.apply_subst subst l in
638 let r = Subst.apply_subst subst r in
639 let o = Order.compare_terms l r in
640 o <> avoid && o <> Terms.Eq
642 let bag, maxvar,r_terms =
643 fold_build_new_clause bag maxvar id Terms.Superposition
646 (fun x -> Terms.Node [ Terms.Leaf B.eqP; ty; l; x ])
647 r (superposition table vl))
649 let bag, maxvar, l_terms =
650 fold_build_new_clause bag maxvar id Terms.Superposition
653 (fun x -> Terms.Node [ Terms.Leaf B.eqP; ty; x; r ])
654 l (superposition table vl))
656 bag, maxvar, r_terms @ l_terms
660 (* the current equation is normal w.r.t. demodulation with atable
661 * (and is not the identity) *)
662 let infer_right bag maxvar current (alist,atable) =
663 (* We demodulate actives clause with current until all *
664 * active clauses are reduced w.r.t each other *)
665 (* let bag, (alist,atable) = keep_simplified (alist,atable) bag [current] in *)
666 let ctable = IDX.index_clause IDX.DT.empty current in
667 (* let bag, (alist, atable) =
669 HExtlib.filter_map_acc (simplify ctable) bag alist
671 bag, (alist, List.fold_left IDX.index_clause IDX.DT.empty alist)
673 debug (lazy "Simplified active clauses with fact");
674 (* We superpose active clauses with current *)
675 let bag, maxvar, new_clauses =
677 (fun (bag, maxvar, acc) active ->
678 let bag, maxvar, newc =
679 superposition_with_table bag maxvar active ctable
681 bag, maxvar, newc @ acc)
682 (bag, maxvar, []) alist
684 debug (lazy "First superpositions");
685 (* We add current to active clauses so that it can be *
686 * superposed with itself *)
688 current :: alist, IDX.index_clause atable current
690 debug (lazy "Indexed");
691 let fresh_current, maxvar = Utils.fresh_clause maxvar current in
692 (* We need to put fresh_current into the bag so that all *
693 * variables clauses refer to are known. *)
694 let bag, fresh_current = Terms.add_to_bag fresh_current bag in
695 (* We superpose current with active clauses *)
696 let bag, maxvar, additional_new_clauses =
697 superposition_with_table bag maxvar fresh_current atable
699 debug (lazy "Another superposition");
700 let new_clauses = new_clauses @ additional_new_clauses in
701 debug (lazy (Printf.sprintf "Demodulating %d clauses"
702 (List.length new_clauses)));
703 let bag, new_clauses =
704 HExtlib.filter_map_monad (simplify atable maxvar) bag new_clauses
706 debug (lazy "Demodulated new clauses");
707 bag, maxvar, (alist, atable), new_clauses
710 let prof_ir = HExtlib.profile ~enable "infer_right";;
711 let infer_right bag maxvar current t =
712 prof_ir.HExtlib.profile (infer_right bag maxvar current) t
715 let infer_left bag maxvar goal (_alist, atable) =
716 (* We superpose the goal with active clauses *)
717 if (match goal with (_,_,_,[],_) -> true | _ -> false) then bag, maxvar, []
719 let bag, maxvar, new_goals =
720 superposition_with_table bag maxvar goal atable
722 debug (lazy "Superposed goal with active clauses");
723 (* We simplify the new goals with active clauses *)
727 match simplify_goal ~no_demod:false maxvar atable bag [] g with
728 | None -> assert false
729 | Some (bag,g) -> bag,g::acc)
732 debug (lazy "Simplified new goals with active clauses");
733 bag, maxvar, List.rev new_goals
736 let prof_il = HExtlib.profile ~enable "infer_left";;
737 let infer_left bag maxvar goal t =
738 prof_il.HExtlib.profile (infer_left bag maxvar goal) t