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
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, 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, (id,lit,vl,_)) ->
142 | Terms.Predicate _ -> assert false
143 | Terms.Equation (l,r,_,o) ->
144 let side, newside = if dir=Terms.Left2Right then l,r else r,l in
147 prof_demod_u.HExtlib.profile
148 (Unif.unification (* (varlist@vl) *) varlist subterm) side
151 prof_demod_s.HExtlib.profile
152 (Subst.apply_subst subst) side
155 prof_demod_s.HExtlib.profile
156 (Subst.apply_subst subst) newside
158 if o = Terms.Incomparable then
160 prof_demod_o.HExtlib.profile
161 (Order.compare_terms newside) side in
162 (* Riazanov, pp. 45 (ii) *)
164 Some (newside, subst, id, dir)
166 ((*prerr_endline ("Filtering: " ^
167 Pp.pp_foterm side ^ " =(< || =)" ^
168 Pp.pp_foterm newside ^ " coming from " ^
169 Pp.pp_unit_clause uc );*)None)
171 Some (newside, subst, id, dir)
172 with FoUnif.UnificationFailure _ -> None)
173 (IDX.ClauseSet.elements cands)
175 let prof_demod = HExtlib.profile ~enable "demod";;
176 let demod table varlist x =
177 prof_demod.HExtlib.profile (demod table varlist) x
180 let demodulate_once_old ~jump_to_right bag (id, literal, vl, pr) table =
182 | Terms.Predicate t -> assert false
183 | Terms.Equation (l,r,ty,_) ->
184 let left_position = if jump_to_right then None else
186 (fun x -> Terms.Node [ Terms.Leaf B.eqP; ty; x; r ]) l
189 match left_position with
190 | Some (newt, subst, id2, dir, pos) ->
192 match build_clause bag (fun _ -> true) Terms.Demodulation
193 newt subst id id2 pos dir
195 | None -> assert false
196 | Some x -> Some (x,false)
200 [3] (fun x -> Terms.Node [ Terms.Leaf B.eqP; ty; l; x ]) r
204 | Some (newt, subst, id2, dir, pos) ->
205 match build_clause bag (fun _ -> true)
206 Terms.Demodulation newt subst id id2 pos dir
208 | None -> assert false
209 | Some x -> Some (x,true)
212 let parallel_demod table vl bag t pos ctx id =
213 match demod table vl t with
215 | Some (newside, subst, id2, dir) ->
216 match build_clause bag (fun _ -> true)
217 Terms.Demodulation (ctx newside) subst id id2 pos dir
219 | None -> assert false
220 | Some (bag,(id,_,_,_)) ->
224 let demodulate_once ~jump_to_right bag (id, literal, vl, pr) table =
226 | Terms.Predicate t -> assert false
227 | Terms.Equation (l,r,ty,_) ->
228 let bag,l,id1 = if jump_to_right then (bag,l,id) else
229 parallel_positions bag [2]
230 (fun x -> Terms.Node [ Terms.Leaf B.eqP; ty; x; r ]) id l
231 (parallel_demod table vl)
233 let jump_to_right = id1 = id in
235 parallel_positions bag [3]
236 (fun x -> Terms.Node [ Terms.Leaf B.eqP; ty; l; x ]) id1 r
237 (parallel_demod table vl)
239 if id = id2 then None
241 let cl,_,_ = Terms.get_from_bag id2 bag in
242 Some ((bag,cl),jump_to_right)
245 let rec demodulate ~jump_to_right bag clause table =
246 match demodulate_once ~jump_to_right bag clause table with
247 | None -> bag, clause
248 | Some ((bag, clause),r) -> demodulate ~jump_to_right:r
252 let rec demodulate_old ~jump_to_right bag clause table =
253 match demodulate_once_old ~jump_to_right bag clause table with
254 | None -> bag, clause
255 | Some ((bag, clause),r) -> demodulate_old ~jump_to_right:r
259 let are_alpha_eq cl1 cl2 =
260 let get_term (_,lit,_,_) =
262 | Terms.Predicate _ -> assert false
263 | Terms.Equation (l,r,ty,_) ->
264 Terms.Node [Terms.Leaf B.eqP; ty; l ; r]
266 try ignore(Unif.alpha_eq (get_term cl1) (get_term cl2)) ; true
267 with FoUnif.UnificationFailure _ -> false
270 let demodulate bag clause table =
271 (* let (bag1,c1), (_,c2) =*)
272 demodulate ~jump_to_right:false bag clause table
273 (* demodulate_old ~jump_to_right:false bag clause table *)
275 if are_alpha_eq c1 c2 then bag1,c1
277 prerr_endline (Pp.pp_unit_clause c1);
278 prerr_endline (Pp.pp_unit_clause c2);
279 prerr_endline "Bag :";
280 prerr_endline (Pp.pp_bag bag1);
284 let prof_demodulate = HExtlib.profile ~enable "demodulate";;
285 let demodulate bag clause x =
286 prof_demodulate.HExtlib.profile (demodulate bag clause) x
290 let is_identity_clause ~unify = function
291 | _, Terms.Equation (_,_,_,Terms.Eq), _, _ -> true
292 | _, Terms.Equation (l,r,_,_), vl, proof when unify ->
293 (try ignore(Unif.unification (* vl *) [] l r); true
294 with FoUnif.UnificationFailure _ -> false)
295 | _, Terms.Equation (_,_,_,_), _, _ -> false
296 | _, Terms.Predicate _, _, _ -> assert false
299 let build_new_clause bag maxvar filter rule t subst id id2 pos dir =
300 let maxvar, _vl, subst = Utils.relocate maxvar (Terms.vars_of_term
301 (Subst.apply_subst subst t)) subst in
302 match build_clause bag filter rule t subst id id2 pos dir with
303 | Some (bag, c) -> Some ((bag, maxvar), c)
306 let prof_build_new_clause = HExtlib.profile ~enable "build_new_clause";;
307 let build_new_clause bag maxvar filter rule t subst id id2 pos x =
308 prof_build_new_clause.HExtlib.profile (build_new_clause bag maxvar filter
309 rule t subst id id2 pos) x
312 let fold_build_new_clause bag maxvar id rule filter res =
313 let (bag, maxvar), res =
314 HExtlib.filter_map_acc
315 (fun (bag, maxvar) (t,subst,id2,pos,dir) ->
316 build_new_clause bag maxvar filter rule t subst id id2 pos dir)
323 let rewrite_eq ~unify l r ty vl table =
324 let retrieve = if unify then IDX.DT.retrieve_unifiables
325 else IDX.DT.retrieve_generalizations in
326 let lcands = retrieve table l in
327 let rcands = retrieve table r in
329 let id, dir, l, r, vl =
331 | (d, (id,Terms.Equation (l,r,ty,_),vl,_))-> id, d, l, r, vl
334 let reverse = (dir = Terms.Left2Right) = b in
335 let l, r, proof_rewrite_dir = if reverse then l,r,Terms.Left2Right
336 else r,l, Terms.Right2Left in
337 (id,proof_rewrite_dir,Terms.Node [ Terms.Leaf B.eqP; ty; l; r ], vl)
339 let cands1 = List.map (f true) (IDX.ClauseSet.elements lcands) in
340 let cands2 = List.map (f false) (IDX.ClauseSet.elements rcands) in
341 let t = Terms.Node [ Terms.Leaf B.eqP; ty; l; r ] in
342 let locked_vars = if unify then [] else vl in
343 let rec aux = function
345 | (id2,dir,c,vl1)::tl ->
347 let subst = Unif.unification (* (vl@vl1) *) locked_vars c t in
348 Some (id2, dir, subst)
349 with FoUnif.UnificationFailure _ -> aux tl
351 aux (cands1 @ cands2)
354 let is_subsumed ~unify bag maxvar (id, lit, vl, _) table =
356 | Terms.Predicate _ -> assert false
357 | Terms.Equation (l,r,ty,_) ->
358 match rewrite_eq ~unify l r ty vl table with
360 | Some (id2, dir, subst) ->
361 let id_t = Terms.Node [ Terms.Leaf B.eqP; ty; r; r ] in
362 build_new_clause bag maxvar (fun _ -> true)
363 Terms.Superposition id_t subst id id2 [2] dir
365 let prof_is_subsumed = HExtlib.profile ~enable "is_subsumed";;
366 let is_subsumed ~unify bag maxvar c x =
367 prof_is_subsumed.HExtlib.profile (is_subsumed ~unify bag maxvar c) x
369 (* id refers to a clause proving contextl l = contextr r *)
371 let rec deep_eq ~unify l r ty pos contextl contextr table acc =
374 | Some(bag,maxvar,(id,lit,vl,p),subst) ->
375 let l = Subst.apply_subst subst l in
376 let r = Subst.apply_subst subst r in
378 let subst1 = Unif.unification (* vl *) [] l r in
380 match lit with Terms.Predicate _ -> assert false
381 | Terms.Equation (l,r,ty,o) ->
382 Terms.Equation (FoSubst.apply_subst subst1 l,
383 FoSubst.apply_subst subst1 r, ty, o)
385 Some(bag,maxvar,(id,lit,vl,p),Subst.concat subst1 subst)
386 with FoUnif.UnificationFailure _ ->
387 match rewrite_eq ~unify l r ty vl table with
388 | Some (id2, dir, subst1) ->
389 let newsubst = Subst.concat subst1 subst in
391 FoSubst.apply_subst newsubst
392 (Terms.Node[Terms.Leaf B.eqP;ty;contextl r;contextr r])
395 build_new_clause bag maxvar (fun _ -> true)
396 Terms.Superposition id_t
397 subst1 id id2 (pos@[2]) dir
399 | Some ((bag, maxvar), c) ->
400 Some(bag,maxvar,c,newsubst)
401 | None -> assert false)
404 | Terms.Node (a::la), Terms.Node (b::lb) when
405 a = b && List.length la = List.length lb ->
408 (fun (acc,pre,postl,postr) a b ->
410 fun x -> contextl(Terms.Node (pre@(x::postl))) in
412 fun x -> contextr(Terms.Node (pre@(x::postr))) in
413 let newpos = List.length pre::pos in
415 if l = [] then [] else List.tl l in
416 (deep_eq ~unify a b ty
417 newpos newcl newcr table acc,pre@[b],
418 footail postl, footail postr))
419 (acc,[a],List.tl la,List.tl lb) la lb
423 let prof_deep_eq = HExtlib.profile ~enable "deep_eq";;
424 let deep_eq ~unify l r ty pos contextl contextr table x =
425 prof_deep_eq.HExtlib.profile (deep_eq ~unify l r ty pos contextl contextr table) x
428 let rec orphan_murder bag acc i =
429 match Terms.get_from_bag i bag with
430 | (_,_,_,Terms.Exact _),discarded,_ -> (discarded,acc)
431 | (_,_,_,Terms.Step (_,i1,i2,_,_,_)),true,_ -> (true,acc)
432 | (_,_,_,Terms.Step (_,i1,i2,_,_,_)),false,_ ->
433 if (List.mem i acc) then (false,acc)
434 else match orphan_murder bag acc i1 with
435 | (true,acc) -> (true,acc)
437 let (res,acc) = orphan_murder bag acc i2 in
438 if res then res,acc else res,i::acc
441 let orphan_murder bag actives cl =
442 let (id,_,_,_) = cl in
443 let actives = List.map (fun (i,_,_,_) -> i) actives in
444 let (res,_) = orphan_murder bag actives id in
445 if res then debug "Orphan murdered"; res
447 let prof_orphan_murder = HExtlib.profile ~enable "orphan_murder";;
448 let orphan_murder bag actives x =
449 prof_orphan_murder.HExtlib.profile (orphan_murder bag actives) x
452 (* demodulate and check for subsumption *)
453 let simplify table maxvar bag clause =
454 if is_identity_clause ~unify:false clause then bag,None
455 (* else if orphan_murder bag actives clause then bag,None *)
456 else let bag, clause = demodulate bag clause table in
457 if is_identity_clause ~unify:false clause then bag,None
459 match is_subsumed ~unify:false bag maxvar clause table with
460 | None -> bag, Some clause
461 | Some _ -> bag, None
464 let simplify table maxvar bag clause =
465 match simplify table maxvar bag clause with
467 let (id,_,_,_) = clause in
468 let (_,_,iter) = Terms.get_from_bag id bag in
469 Terms.replace_in_bag (clause,true,iter) bag, None
470 | bag, Some clause -> bag, Some clause
471 (*let (id,_,_,_) = clause in
472 if orphan_murder bag clause then
473 Terms.M.add id (clause,true) bag, Some clause
474 else bag, Some clause*)
476 let prof_simplify = HExtlib.profile ~enable "simplify";;
477 let simplify table maxvar bag x =
478 prof_simplify.HExtlib.profile (simplify table maxvar bag ) x
481 let one_pass_simplification new_clause (alist,atable) bag maxvar =
482 match simplify atable maxvar bag new_clause with
483 | bag,None -> bag,None (* new_clause has been discarded *)
484 | bag,(Some clause) ->
485 let ctable = IDX.index_unit_clause maxvar IDX.DT.empty clause in
486 let bag, alist, atable =
488 (fun (bag, alist, atable) c ->
489 match simplify ctable maxvar bag c with
490 |bag,None -> (bag,alist,atable)
491 (* an active clause as been discarded *)
493 bag, c :: alist, IDX.index_unit_clause maxvar atable c)
494 (bag,[],IDX.DT.empty) alist
496 bag, Some (clause, (alist,atable))
498 let prof_one_pass_simplification = HExtlib.profile ~enable "one_pass_simplification";;
499 let one_pass_simplification new_clause t bag x =
500 prof_one_pass_simplification.HExtlib.profile (one_pass_simplification new_clause t bag ) x
503 let simplification_step ~new_cl cl (alist,atable) bag maxvar new_clause =
505 if new_cl then atable else
506 IDX.index_unit_clause maxvar atable cl
508 (* Simplification of new_clause with : *
509 * - actives and cl if new_clause is not cl *
510 * - only actives otherwise *)
512 simplify atable1 maxvar bag new_clause with
513 | bag,None -> bag,(Some cl, None) (* new_clause has been discarded *)
515 (* Simplification of each active clause with clause *
516 * which is the simplified form of new_clause *)
517 let ctable = IDX.index_unit_clause maxvar IDX.DT.empty clause in
518 let bag, newa, alist, atable =
520 (fun (bag, newa, alist, atable) c ->
521 match simplify ctable maxvar bag c with
522 |bag,None -> (bag, newa, alist, atable)
523 (* an active clause as been discarded *)
526 bag, newa, c :: alist,
527 IDX.index_unit_clause maxvar atable c
529 bag, c1 :: newa, alist, atable)
530 (bag,[],[],IDX.DT.empty) alist
533 bag, (Some cl, Some (clause, (alist,atable), newa))
535 (* if new_clause is not cl, we simplify cl with clause *)
536 match simplify ctable maxvar bag cl with
538 (* cl has been discarded *)
539 bag,(None, Some (clause, (alist,atable), newa))
541 bag,(Some cl1, Some (clause, (alist,atable), newa))
543 let prof_simplification_step = HExtlib.profile ~enable "simplification_step";;
544 let simplification_step ~new_cl cl (alist,atable) bag maxvar x =
545 prof_simplification_step.HExtlib.profile (simplification_step ~new_cl cl (alist,atable) bag maxvar) x
548 let keep_simplified cl (alist,atable) bag maxvar =
549 let rec keep_simplified_aux ~new_cl cl (alist,atable) bag newc =
551 match simplification_step ~new_cl cl (alist,atable) bag maxvar cl with
552 | _,(None, _) -> assert false
553 | bag,(Some _, None) -> bag,None
554 | bag,(Some _, Some (clause, (alist,atable), newa)) ->
555 keep_simplified_aux ~new_cl:(cl!=clause) clause (alist,atable)
559 | [] -> bag, Some (cl, (alist,atable))
561 match simplification_step ~new_cl cl
562 (alist,atable) bag maxvar hd with
563 | _,(None,None) -> assert false
564 | bag,(Some _,None) ->
565 keep_simplified_aux ~new_cl cl (alist,atable) bag tl
566 | bag,(None, Some _) -> bag,None
567 | bag,(Some cl1, Some (clause, (alist,atable), newa)) ->
569 (clause::alist, IDX.index_unit_clause maxvar atable clause)
571 keep_simplified_aux ~new_cl:(cl!=cl1) cl1 (alist,atable)
574 keep_simplified_aux ~new_cl:true cl (alist,atable) bag []
576 let prof_keep_simplified = HExtlib.profile ~enable "keep_simplified";;
577 let keep_simplified cl t bag x =
578 prof_keep_simplified.HExtlib.profile (keep_simplified cl t bag) x
581 (* this is like simplify but raises Success *)
582 let simplify_goal ~no_demod maxvar table bag g_actives clause =
584 if no_demod then bag, clause else demodulate bag clause table
586 if List.exists (are_alpha_eq clause) g_actives then None else
587 if (is_identity_clause ~unify:true clause)
588 then raise (Success (bag, maxvar, clause))
590 let (id,lit,vl,_) = clause in
591 if vl = [] then Some (bag,clause)
595 | Terms.Equation(l,r,ty,_) -> l,r,ty
598 match deep_eq ~unify:true l r ty [] (fun x -> x) (fun x -> x)
599 table (Some(bag,maxvar,clause,Subst.id_subst)) with
600 | None -> Some (bag,clause)
601 | Some (bag,maxvar,cl,subst) ->
602 prerr_endline "Goal subsumed";
603 raise (Success (bag,maxvar,cl))
605 else match is_subsumed ~unify:true bag maxvar clause table with
606 | None -> Some (bag, clause)
607 | Some ((bag,maxvar),c) ->
608 prerr_endline "Goal subsumed";
609 raise (Success (bag,maxvar,c))
613 let prof_simplify_goal = HExtlib.profile ~enable "simplify_goal";;
614 let simplify_goal ~no_demod maxvar table bag g_actives x =
615 prof_simplify_goal.HExtlib.profile ( simplify_goal ~no_demod maxvar table bag g_actives) x
618 (* =================== inference ===================== *)
620 (* this is OK for both the sup_left and sup_right inference steps *)
621 let superposition table varlist subterm pos context =
622 let cands = IDX.DT.retrieve_unifiables table subterm in
624 (fun (dir, (id,lit,vl,_ (*as uc*))) ->
626 | Terms.Predicate _ -> assert false
627 | Terms.Equation (l,r,_,o) ->
628 let side, newside = if dir=Terms.Left2Right then l,r else r,l in
631 Unif.unification (* (varlist@vl)*) [] subterm side
633 if o = Terms.Incomparable then
634 let side = Subst.apply_subst subst side in
635 let newside = Subst.apply_subst subst newside in
636 let o = Order.compare_terms side newside in
637 (* XXX: check Riazanov p. 33 (iii) *)
638 if o <> Terms.Lt && o <> Terms.Eq then
639 Some (context newside, subst, id, pos, dir)
641 ((*prerr_endline ("Filtering: " ^
642 Pp.pp_foterm side ^ " =(< || =)" ^
643 Pp.pp_foterm newside);*)None)
645 Some (context newside, subst, id, pos, dir)
646 with FoUnif.UnificationFailure _ -> None)
647 (IDX.ClauseSet.elements cands)
650 (* Superposes selected equation with equalities in table *)
651 let superposition_with_table bag maxvar (id,selected,vl,_) table =
653 | Terms.Predicate _ -> assert false
654 | Terms.Equation (l,r,ty,Terms.Lt) ->
655 fold_build_new_clause bag maxvar id Terms.Superposition
658 (fun x -> Terms.Node [ Terms.Leaf B.eqP; ty; l; x ])
659 r (superposition table vl))
660 | Terms.Equation (l,r,ty,Terms.Gt) ->
661 fold_build_new_clause bag maxvar id Terms.Superposition
664 (fun x -> Terms.Node [ Terms.Leaf B.eqP; ty; x; r ])
665 l (superposition table vl))
666 | Terms.Equation (l,r,ty,Terms.Incomparable) ->
667 let filtering avoid subst = (* Riazanov: p.33 condition (iv) *)
668 let l = Subst.apply_subst subst l in
669 let r = Subst.apply_subst subst r in
670 let o = Order.compare_terms l r in
671 o <> avoid && o <> Terms.Eq
673 let bag, maxvar,r_terms =
674 fold_build_new_clause bag maxvar id Terms.Superposition
677 (fun x -> Terms.Node [ Terms.Leaf B.eqP; ty; l; x ])
678 r (superposition table vl))
680 let bag, maxvar, l_terms =
681 fold_build_new_clause bag maxvar id Terms.Superposition
684 (fun x -> Terms.Node [ Terms.Leaf B.eqP; ty; l; x ])
685 r (superposition table vl))
687 bag, maxvar, r_terms @ l_terms
691 (* the current equation is normal w.r.t. demodulation with atable
692 * (and is not the identity) *)
693 let infer_right bag maxvar current (alist,atable) =
694 (* We demodulate actives clause with current until all *
695 * active clauses are reduced w.r.t each other *)
696 (* let bag, (alist,atable) = keep_simplified (alist,atable) bag [current] in *)
697 let ctable = IDX.index_unit_clause maxvar IDX.DT.empty current in
698 (* let bag, (alist, atable) =
700 HExtlib.filter_map_acc (simplify ctable) bag alist
702 bag, (alist, List.fold_left IDX.index_unit_clause IDX.DT.empty alist)
704 debug "Simplified active clauses with fact";
705 (* We superpose active clauses with current *)
706 let bag, maxvar, new_clauses =
708 (fun (bag, maxvar, acc) active ->
709 let bag, maxvar, newc =
710 superposition_with_table bag maxvar active ctable
712 bag, maxvar, newc @ acc)
713 (bag, maxvar, []) alist
715 debug "First superpositions";
716 (* We add current to active clauses so that it can be *
717 * superposed with itself *)
719 current :: alist, IDX.index_unit_clause maxvar atable current
722 let fresh_current, maxvar = Utils.fresh_unit_clause maxvar current in
723 (* We need to put fresh_current into the bag so that all *
724 * variables clauses refer to are known. *)
725 let bag, fresh_current = Terms.add_to_bag fresh_current bag in
726 (* We superpose current with active clauses *)
727 let bag, maxvar, additional_new_clauses =
728 superposition_with_table bag maxvar fresh_current atable
730 debug "Another superposition";
731 let new_clauses = new_clauses @ additional_new_clauses in
732 debug (Printf.sprintf "Demodulating %d clauses"
733 (List.length new_clauses));
734 let bag, new_clauses =
735 HExtlib.filter_map_monad (simplify atable maxvar) bag new_clauses
737 debug "Demodulated new clauses";
738 bag, maxvar, (alist, atable), new_clauses
741 let prof_ir = HExtlib.profile ~enable "infer_right";;
742 let infer_right bag maxvar current t =
743 prof_ir.HExtlib.profile (infer_right bag maxvar current) t
746 let infer_left bag maxvar goal (_alist, atable) =
747 (* We superpose the goal with active clauses *)
748 if (match goal with (_,_,[],_) -> true | _ -> false) then bag, maxvar, []
750 let bag, maxvar, new_goals =
751 superposition_with_table bag maxvar goal atable
753 debug "Superposed goal with active clauses";
754 (* We simplify the new goals with active clauses *)
758 match simplify_goal ~no_demod:false maxvar atable bag [] g with
759 | None -> assert false
760 | Some (bag,g) -> bag,g::acc)
763 debug "Simplified new goals with active clauses";
764 bag, maxvar, List.rev new_goals
767 let prof_il = HExtlib.profile ~enable "infer_left";;
768 let infer_left bag maxvar goal t =
769 prof_il.HExtlib.profile (infer_left bag maxvar goal) t