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.unit_clause
25 let debug s = prerr_endline 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
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, [], List.tl l, id) l
103 let build_clause bag filter rule t subst id id2 pos dir =
104 let proof = Terms.Step(rule,id,id2,dir,pos,subst) in
105 let t = Subst.apply_subst subst t in
109 | Terms.Node [ Terms.Leaf eq ; ty; l; r ] when B.eq B.eqP eq ->
110 let o = Order.compare_terms l r in
111 Terms.Equation (l, r, ty, o)
112 | t -> Terms.Predicate t
115 Terms.add_to_bag (0, literal, Terms.vars_of_term t, proof) bag
119 ((*prerr_endline ("Filtering: " ^ Pp.pp_foterm t);*)None)
121 let prof_build_clause = HExtlib.profile ~enable "build_clause";;
122 let build_clause bag filter rule t subst id id2 pos x =
123 prof_build_clause.HExtlib.profile (build_clause bag filter rule t subst id id2 pos) x
127 (* ============ simplification ================= *)
128 let prof_demod_u = HExtlib.profile ~enable "demod.unify";;
129 let prof_demod_r = HExtlib.profile ~enable "demod.retrieve_generalizations";;
130 let prof_demod_o = HExtlib.profile ~enable "demod.compare_terms";;
132 let demod table varlist subterm =
134 prof_demod_r.HExtlib.profile
135 (IDX.DT.retrieve_generalizations table) subterm
138 (fun (dir, (id,lit,vl,_)) ->
140 | Terms.Predicate _ -> assert false
141 | Terms.Equation (l,r,_,o) ->
142 let side, newside = if dir=Terms.Left2Right then l,r else r,l in
145 prof_demod_u.HExtlib.profile
146 (Unif.unification (varlist@vl) varlist subterm) side
148 let side = Subst.apply_subst subst side in
149 let newside = Subst.apply_subst subst newside in
150 if o = Terms.Incomparable then
152 prof_demod_o.HExtlib.profile
153 (Order.compare_terms newside) side in
154 (* Riazanov, pp. 45 (ii) *)
156 Some (newside, subst, id, dir)
158 ((*prerr_endline ("Filtering: " ^
159 Pp.pp_foterm side ^ " =(< || =)" ^
160 Pp.pp_foterm newside ^ " coming from " ^
161 Pp.pp_unit_clause uc );*)None)
163 Some (newside, subst, id, dir)
164 with FoUnif.UnificationFailure _ -> None)
165 (IDX.ClauseSet.elements cands)
167 let prof_demod = HExtlib.profile ~enable "demod";;
168 let demod table varlist x =
169 prof_demod.HExtlib.profile (demod table varlist) x
172 let demodulate_once_old ~jump_to_right bag (id, literal, vl, pr) table =
174 | Terms.Predicate t -> assert false
175 | Terms.Equation (l,r,ty,_) ->
176 let left_position = if jump_to_right then None else
178 (fun x -> Terms.Node [ Terms.Leaf B.eqP; ty; x; r ]) l
181 match left_position with
182 | Some (newt, subst, id2, dir, pos) ->
184 match build_clause bag (fun _ -> true) Terms.Demodulation
185 newt subst id id2 pos dir
187 | None -> assert false
188 | Some x -> Some (x,false)
192 [3] (fun x -> Terms.Node [ Terms.Leaf B.eqP; ty; l; x ]) r
196 | Some (newt, subst, id2, dir, pos) ->
197 match build_clause bag (fun _ -> true)
198 Terms.Demodulation newt subst id id2 pos dir
200 | None -> assert false
201 | Some x -> Some (x,true)
204 let parallel_demod table vl bag t pos ctx id =
205 match demod table vl t with
207 | Some (newside, subst, id2, dir) ->
208 match build_clause bag (fun _ -> true)
209 Terms.Demodulation (ctx newside) subst id id2 pos dir
211 | None -> assert false
212 | Some (bag,(id,_,_,_)) ->
216 let demodulate_once ~jump_to_right bag (id, literal, vl, pr) table =
218 | Terms.Predicate t -> assert false
219 | Terms.Equation (l,r,ty,_) ->
220 let bag,l,id1 = if jump_to_right then (bag,l,id) else
221 parallel_positions bag [2]
222 (fun x -> Terms.Node [ Terms.Leaf B.eqP; ty; x; r ]) id l
223 (parallel_demod table vl)
225 let jump_to_right = id1 = id in
227 parallel_positions bag [3]
228 (fun x -> Terms.Node [ Terms.Leaf B.eqP; ty; l; x ]) id1 r
229 (parallel_demod table vl)
231 if id = id2 then None
233 let cl,_,_ = Terms.get_from_bag id2 bag in
234 Some ((bag,cl),jump_to_right)
237 let rec demodulate ~jump_to_right bag clause table =
238 match demodulate_once ~jump_to_right bag clause table with
239 | None -> bag, clause
240 | Some ((bag, clause),r) -> demodulate ~jump_to_right:r
244 let rec demodulate_old ~jump_to_right bag clause table =
245 match demodulate_once_old ~jump_to_right bag clause table with
246 | None -> bag, clause
247 | Some ((bag, clause),r) -> demodulate_old ~jump_to_right:r
251 let are_alpha_eq cl1 cl2 =
252 let get_term (_,lit,_,_) =
254 | Terms.Predicate _ -> assert false
255 | Terms.Equation (l,r,ty,_) ->
256 Terms.Node [Terms.Leaf B.eqP; ty; l ; r]
258 try ignore(Unif.alpha_eq (get_term cl1) (get_term cl2)) ; true
259 with FoUnif.UnificationFailure _ -> false
262 let demodulate bag clause table =
263 (* let (bag1,c1), (_,c2) =*)
264 demodulate ~jump_to_right:false bag clause table
265 (* demodulate_old ~jump_to_right:false bag clause table *)
267 if are_alpha_eq c1 c2 then bag1,c1
269 prerr_endline (Pp.pp_unit_clause c1);
270 prerr_endline (Pp.pp_unit_clause c2);
271 prerr_endline "Bag :";
272 prerr_endline (Pp.pp_bag bag1);
276 let prof_demodulate = HExtlib.profile ~enable "demodulate";;
277 let demodulate bag clause x =
278 prof_demodulate.HExtlib.profile (demodulate bag clause) x
282 let is_identity_clause ~unify = function
283 | _, Terms.Equation (_,_,_,Terms.Eq), _, _ -> true
284 | _, Terms.Equation (l,r,_,_), vl, proof when unify ->
285 (try ignore(Unif.unification vl [] l r); true
286 with FoUnif.UnificationFailure _ -> false)
287 | _, Terms.Equation (_,_,_,_), _, _ -> false
288 | _, Terms.Predicate _, _, _ -> assert false
291 let build_new_clause bag maxvar filter rule t subst id id2 pos dir =
292 let maxvar, _vl, subst = Utils.relocate maxvar (Terms.vars_of_term
293 (Subst.apply_subst subst t)) subst in
294 match build_clause bag filter rule t subst id id2 pos dir with
295 | Some (bag, c) -> Some ((bag, maxvar), c)
298 let prof_build_new_clause = HExtlib.profile ~enable "build_new_clause";;
299 let build_new_clause bag maxvar filter rule t subst id id2 pos x =
300 prof_build_new_clause.HExtlib.profile (build_new_clause bag maxvar filter
301 rule t subst id id2 pos) x
304 let fold_build_new_clause bag maxvar id rule filter res =
305 let (bag, maxvar), res =
306 HExtlib.filter_map_acc
307 (fun (bag, maxvar) (t,subst,id2,pos,dir) ->
308 build_new_clause bag maxvar filter rule t subst id id2 pos dir)
315 let rewrite_eq ~unify l r ty vl table =
316 let retrieve = if unify then IDX.DT.retrieve_unifiables
317 else IDX.DT.retrieve_generalizations in
318 let lcands = retrieve table l in
319 let rcands = retrieve table r in
321 let id, dir, l, r, vl =
323 | (d, (id,Terms.Equation (l,r,ty,_),vl,_))-> id, d, l, r, vl
326 let reverse = (dir = Terms.Left2Right) = b in
327 let l, r, proof_rewrite_dir = if reverse then l,r,Terms.Left2Right
328 else r,l, Terms.Right2Left in
329 (id,proof_rewrite_dir,Terms.Node [ Terms.Leaf B.eqP; ty; l; r ], vl)
331 let cands1 = List.map (f true) (IDX.ClauseSet.elements lcands) in
332 let cands2 = List.map (f false) (IDX.ClauseSet.elements rcands) in
333 let t = Terms.Node [ Terms.Leaf B.eqP; ty; l; r ] in
334 let locked_vars = if unify then [] else vl in
335 let rec aux = function
337 | (id2,dir,c,vl1)::tl ->
339 let subst = Unif.unification (vl@vl1) locked_vars c t in
340 Some (id2, dir, subst)
341 with FoUnif.UnificationFailure _ -> aux tl
343 aux (cands1 @ cands2)
346 let is_subsumed ~unify bag maxvar (id, lit, vl, _) table =
348 | Terms.Predicate _ -> assert false
349 | Terms.Equation (l,r,ty,_) ->
350 match rewrite_eq ~unify l r ty vl table with
352 | Some (id2, dir, subst) ->
353 let id_t = Terms.Node [ Terms.Leaf B.eqP; ty; r; r ] in
354 build_new_clause bag maxvar (fun _ -> true)
355 Terms.Superposition id_t subst id id2 [2] dir
357 let prof_is_subsumed = HExtlib.profile ~enable "is_subsumed";;
358 let is_subsumed ~unify bag maxvar c x =
359 prof_is_subsumed.HExtlib.profile (is_subsumed ~unify bag maxvar c) x
361 (* id refers to a clause proving contextl l = contextr r *)
363 let rec deep_eq ~unify l r ty pos contextl contextr table acc =
366 | Some(bag,maxvar,(id,lit,vl,p),subst) ->
367 let l = Subst.apply_subst subst l in
368 let r = Subst.apply_subst subst r in
370 let subst1 = Unif.unification vl [] l r in
372 match lit with Terms.Predicate _ -> assert false
373 | Terms.Equation (l,r,ty,o) ->
374 Terms.Equation (FoSubst.apply_subst subst1 l,
375 FoSubst.apply_subst subst1 r, ty, o)
377 Some(bag,maxvar,(id,lit,vl,p),Subst.concat subst1 subst)
378 with FoUnif.UnificationFailure _ ->
379 match rewrite_eq ~unify l r ty vl table with
380 | Some (id2, dir, subst1) ->
381 let newsubst = Subst.concat subst1 subst in
383 FoSubst.apply_subst newsubst
384 (Terms.Node[Terms.Leaf B.eqP;ty;contextl r;contextr r])
387 build_new_clause bag maxvar (fun _ -> true)
388 Terms.Superposition id_t
389 subst1 id id2 (pos@[2]) dir
391 | Some ((bag, maxvar), c) ->
392 Some(bag,maxvar,c,newsubst)
393 | None -> assert false)
396 | Terms.Node (a::la), Terms.Node (b::lb) when
397 a = b && List.length la = List.length lb ->
400 (fun (acc,pre,postl,postr) a b ->
402 fun x -> contextl(Terms.Node (pre@(x::postl))) in
404 fun x -> contextr(Terms.Node (pre@(x::postr))) in
405 let newpos = List.length pre::pos in
407 if l = [] then [] else List.tl l in
408 (deep_eq ~unify a b ty
409 newpos newcl newcr table acc,pre@[b],
410 footail postl, footail postr))
411 (acc,[a],List.tl la,List.tl lb) la lb
415 let prof_deep_eq = HExtlib.profile ~enable "deep_eq";;
416 let deep_eq ~unify l r ty pos contextl contextr table x =
417 prof_deep_eq.HExtlib.profile (deep_eq ~unify l r ty pos contextl contextr table) x
420 let rec orphan_murder bag acc i =
421 match Terms.get_from_bag i bag with
422 | (_,_,_,Terms.Exact _),discarded,_ -> (discarded,acc)
423 | (_,_,_,Terms.Step (_,i1,i2,_,_,_)),true,_ -> (true,acc)
424 | (_,_,_,Terms.Step (_,i1,i2,_,_,_)),false,_ ->
425 if (List.mem i acc) then (false,acc)
426 else match orphan_murder bag acc i1 with
427 | (true,acc) -> (true,acc)
429 let (res,acc) = orphan_murder bag acc i2 in
430 if res then res,acc else res,i::acc
433 let orphan_murder bag actives cl =
434 let (id,_,_,_) = cl in
435 let actives = List.map (fun (i,_,_,_) -> i) actives in
436 let (res,_) = orphan_murder bag actives id in
437 if res then debug "Orphan murdered"; res
439 let prof_orphan_murder = HExtlib.profile ~enable "orphan_murder";;
440 let orphan_murder bag actives x =
441 prof_orphan_murder.HExtlib.profile (orphan_murder bag actives) x
444 (* demodulate and check for subsumption *)
445 let simplify table maxvar bag clause =
446 if is_identity_clause ~unify:false clause then bag,None
447 (* else if orphan_murder bag actives clause then bag,None *)
448 else let bag, clause = demodulate bag clause table in
449 if is_identity_clause ~unify:false clause then bag,None
451 match is_subsumed ~unify:false bag maxvar clause table with
452 | None -> bag, Some clause
453 | Some _ -> bag, None
456 let simplify table maxvar bag clause =
457 match simplify table maxvar bag clause with
459 let (id,_,_,_) = clause in
460 let (_,_,iter) = Terms.get_from_bag id bag in
461 Terms.replace_in_bag (clause,true,iter) bag, None
462 | bag, Some clause -> bag, Some clause
463 (*let (id,_,_,_) = clause in
464 if orphan_murder bag clause then
465 Terms.M.add id (clause,true) bag, Some clause
466 else bag, Some clause*)
468 let prof_simplify = HExtlib.profile ~enable "simplify";;
469 let simplify table maxvar bag x =
470 prof_simplify.HExtlib.profile (simplify table maxvar bag ) x
473 let one_pass_simplification new_clause (alist,atable) bag maxvar =
474 match simplify atable maxvar bag new_clause with
475 | bag,None -> bag,None (* new_clause has been discarded *)
476 | bag,(Some clause) ->
477 let ctable = IDX.index_unit_clause IDX.DT.empty clause in
478 let bag, alist, atable =
480 (fun (bag, alist, atable) c ->
481 match simplify ctable maxvar bag c with
482 |bag,None -> (bag,alist,atable)
483 (* an active clause as been discarded *)
485 bag, c :: alist, IDX.index_unit_clause atable c)
486 (bag,[],IDX.DT.empty) alist
488 bag, Some (clause, (alist,atable))
490 let prof_one_pass_simplification = HExtlib.profile ~enable "one_pass_simplification";;
491 let one_pass_simplification new_clause t bag x =
492 prof_one_pass_simplification.HExtlib.profile (one_pass_simplification new_clause t bag ) x
495 let simplification_step ~new_cl cl (alist,atable) bag maxvar new_clause =
497 if new_cl then atable else
498 IDX.index_unit_clause atable cl
500 (* Simplification of new_clause with : *
501 * - actives and cl if new_clause is not cl *
502 * - only actives otherwise *)
504 simplify atable1 maxvar bag new_clause with
505 | bag,None -> bag,(Some cl, None) (* new_clause has been discarded *)
507 (* Simplification of each active clause with clause *
508 * which is the simplified form of new_clause *)
509 let ctable = IDX.index_unit_clause IDX.DT.empty clause in
510 let bag, newa, alist, atable =
512 (fun (bag, newa, alist, atable) c ->
513 match simplify ctable maxvar bag c with
514 |bag,None -> (bag, newa, alist, atable)
515 (* an active clause as been discarded *)
518 bag, newa, c :: alist,
519 IDX.index_unit_clause atable c
521 bag, c1 :: newa, alist, atable)
522 (bag,[],[],IDX.DT.empty) alist
525 bag, (Some cl, Some (clause, (alist,atable), newa))
527 (* if new_clause is not cl, we simplify cl with clause *)
528 match simplify ctable maxvar bag cl with
530 (* cl has been discarded *)
531 bag,(None, Some (clause, (alist,atable), newa))
533 bag,(Some cl1, Some (clause, (alist,atable), newa))
535 let prof_simplification_step = HExtlib.profile ~enable "simplification_step";;
536 let simplification_step ~new_cl cl (alist,atable) bag maxvar x =
537 prof_simplification_step.HExtlib.profile (simplification_step ~new_cl cl (alist,atable) bag maxvar) x
540 let keep_simplified cl (alist,atable) bag maxvar =
541 let rec keep_simplified_aux ~new_cl cl (alist,atable) bag newc =
543 match simplification_step ~new_cl cl (alist,atable) bag maxvar cl with
544 | _,(None, _) -> assert false
545 | bag,(Some _, None) -> bag,None
546 | bag,(Some _, Some (clause, (alist,atable), newa)) ->
547 keep_simplified_aux ~new_cl:(cl!=clause) clause (alist,atable)
551 | [] -> bag, Some (cl, (alist,atable))
553 match simplification_step ~new_cl cl
554 (alist,atable) bag maxvar hd with
555 | _,(None,None) -> assert false
556 | bag,(Some _,None) ->
557 keep_simplified_aux ~new_cl cl (alist,atable) bag tl
558 | bag,(None, Some _) -> bag,None
559 | bag,(Some cl1, Some (clause, (alist,atable), newa)) ->
561 (clause::alist, IDX.index_unit_clause atable clause)
563 keep_simplified_aux ~new_cl:(cl!=cl1) cl1 (alist,atable)
566 keep_simplified_aux ~new_cl:true cl (alist,atable) bag []
568 let prof_keep_simplified = HExtlib.profile ~enable "keep_simplified";;
569 let keep_simplified cl t bag x =
570 prof_keep_simplified.HExtlib.profile (keep_simplified cl t bag) x
573 (* this is like simplify but raises Success *)
574 let simplify_goal ~no_demod maxvar table bag g_actives clause =
576 if no_demod then bag, clause else demodulate bag clause table
578 if List.exists (are_alpha_eq clause) g_actives then None else
579 if (is_identity_clause ~unify:true clause)
580 then raise (Success (bag, maxvar, clause))
582 let (id,lit,vl,_) = clause in
583 if vl = [] then Some (bag,clause)
587 | Terms.Equation(l,r,ty,_) -> l,r,ty
590 match deep_eq ~unify:true l r ty [] (fun x -> x) (fun x -> x)
591 table (Some(bag,maxvar,clause,Subst.id_subst)) with
592 | None -> Some (bag,clause)
593 | Some (bag,maxvar,cl,subst) ->
594 prerr_endline "Goal subsumed";
595 raise (Success (bag,maxvar,cl))
597 else match is_subsumed ~unify:true bag maxvar clause table with
598 | None -> Some (bag, clause)
599 | Some ((bag,maxvar),c) ->
600 prerr_endline "Goal subsumed";
601 raise (Success (bag,maxvar,c))
605 let prof_simplify_goal = HExtlib.profile ~enable "simplify_goal";;
606 let simplify_goal ~no_demod maxvar table bag g_actives x =
607 prof_simplify_goal.HExtlib.profile ( simplify_goal ~no_demod maxvar table bag g_actives) x
610 (* =================== inference ===================== *)
612 (* this is OK for both the sup_left and sup_right inference steps *)
613 let superposition table varlist subterm pos context =
614 let cands = IDX.DT.retrieve_unifiables table subterm in
616 (fun (dir, (id,lit,vl,_ (*as uc*))) ->
618 | Terms.Predicate _ -> assert false
619 | Terms.Equation (l,r,_,o) ->
620 let side, newside = if dir=Terms.Left2Right then l,r else r,l in
623 Unif.unification (varlist@vl) [] subterm side
625 if o = Terms.Incomparable then
626 let side = Subst.apply_subst subst side in
627 let newside = Subst.apply_subst subst newside in
628 let o = Order.compare_terms side newside in
629 (* XXX: check Riazanov p. 33 (iii) *)
630 if o <> Terms.Lt && o <> Terms.Eq then
631 Some (context newside, subst, id, pos, dir)
633 ((*prerr_endline ("Filtering: " ^
634 Pp.pp_foterm side ^ " =(< || =)" ^
635 Pp.pp_foterm newside);*)None)
637 Some (context newside, subst, id, pos, dir)
638 with FoUnif.UnificationFailure _ -> None)
639 (IDX.ClauseSet.elements cands)
642 (* Superposes selected equation with equalities in table *)
643 let superposition_with_table bag maxvar (id,selected,vl,_) table =
645 | Terms.Predicate _ -> assert false
646 | Terms.Equation (l,r,ty,Terms.Lt) ->
647 fold_build_new_clause bag maxvar id Terms.Superposition
650 (fun x -> Terms.Node [ Terms.Leaf B.eqP; ty; l; x ])
651 r (superposition table vl))
652 | Terms.Equation (l,r,ty,Terms.Gt) ->
653 fold_build_new_clause bag maxvar id Terms.Superposition
656 (fun x -> Terms.Node [ Terms.Leaf B.eqP; ty; x; r ])
657 l (superposition table vl))
658 | Terms.Equation (l,r,ty,Terms.Incomparable) ->
659 let filtering avoid subst = (* Riazanov: p.33 condition (iv) *)
660 let l = Subst.apply_subst subst l in
661 let r = Subst.apply_subst subst r in
662 let o = Order.compare_terms l r in
663 o <> avoid && o <> Terms.Eq
665 let bag, maxvar,r_terms =
666 fold_build_new_clause bag maxvar id Terms.Superposition
669 (fun x -> Terms.Node [ Terms.Leaf B.eqP; ty; l; x ])
670 r (superposition table vl))
672 let bag, maxvar, l_terms =
673 fold_build_new_clause bag maxvar id Terms.Superposition
676 (fun x -> Terms.Node [ Terms.Leaf B.eqP; ty; l; x ])
677 r (superposition table vl))
679 bag, maxvar, r_terms @ l_terms
683 (* the current equation is normal w.r.t. demodulation with atable
684 * (and is not the identity) *)
685 let infer_right bag maxvar current (alist,atable) =
686 (* We demodulate actives clause with current until all *
687 * active clauses are reduced w.r.t each other *)
688 (* let bag, (alist,atable) = keep_simplified (alist,atable) bag [current] in *)
689 let ctable = IDX.index_unit_clause IDX.DT.empty current in
690 (* let bag, (alist, atable) =
692 HExtlib.filter_map_acc (simplify ctable) bag alist
694 bag, (alist, List.fold_left IDX.index_unit_clause IDX.DT.empty alist)
696 debug "Simplified active clauses with fact";
697 (* We superpose active clauses with current *)
698 let bag, maxvar, new_clauses =
700 (fun (bag, maxvar, acc) active ->
701 let bag, maxvar, newc =
702 superposition_with_table bag maxvar active ctable
704 bag, maxvar, newc @ acc)
705 (bag, maxvar, []) alist
707 debug "First superpositions";
708 (* We add current to active clauses so that it can be *
709 * superposed with itself *)
711 current :: alist, IDX.index_unit_clause atable current
714 let fresh_current, maxvar = Utils.fresh_unit_clause maxvar current in
715 (* We need to put fresh_current into the bag so that all *
716 * variables clauses refer to are known. *)
717 let bag, fresh_current = Terms.add_to_bag fresh_current bag in
718 (* We superpose current with active clauses *)
719 let bag, maxvar, additional_new_clauses =
720 superposition_with_table bag maxvar fresh_current atable
722 debug "Another superposition";
723 let new_clauses = new_clauses @ additional_new_clauses in
724 debug (Printf.sprintf "Demodulating %d clauses"
725 (List.length new_clauses));
726 let bag, new_clauses =
727 HExtlib.filter_map_monad (simplify atable maxvar) bag new_clauses
729 debug "Demodulated new clauses";
730 bag, maxvar, (alist, atable), new_clauses
733 let prof_ir = HExtlib.profile ~enable "infer_right";;
734 let infer_right bag maxvar current t =
735 prof_ir.HExtlib.profile (infer_right bag maxvar current) t
738 let infer_left bag maxvar goal (_alist, atable) =
739 (* We superpose the goal with active clauses *)
740 if (match goal with (_,_,[],_) -> true | _ -> false) then bag, maxvar, []
742 let bag, maxvar, new_goals =
743 superposition_with_table bag maxvar goal atable
745 debug "Superposed goal with active clauses";
746 (* We simplify the new goals with active clauses *)
750 match simplify_goal ~no_demod:false maxvar atable bag [] g with
751 | None -> assert false
752 | Some (bag,g) -> bag,g::acc)
755 debug "Simplified new goals with active clauses";
756 bag, maxvar, List.rev new_goals
759 let prof_il = HExtlib.profile ~enable "infer_left";;
760 let infer_left bag maxvar goal t =
761 prof_il.HExtlib.profile (infer_left bag maxvar goal) t