X-Git-Url: http://matita.cs.unibo.it/gitweb/?p=helm.git;a=blobdiff_plain;f=helm%2Focaml%2Fparamodulation%2Findexing.ml;fp=helm%2Focaml%2Fparamodulation%2Findexing.ml;h=2d9076ad5fd1e389d5d94f5fce3230d9b972d862;hp=0000000000000000000000000000000000000000;hb=792b5d29ebae8f917043d9dd226692919b5d6ca1;hpb=a14a8c7637fd0b95e9d4deccb20c6abc98e8f953 diff --git a/helm/ocaml/paramodulation/indexing.ml b/helm/ocaml/paramodulation/indexing.ml new file mode 100644 index 000000000..2d9076ad5 --- /dev/null +++ b/helm/ocaml/paramodulation/indexing.ml @@ -0,0 +1,1021 @@ +(* Copyright (C) 2005, HELM Team. + * + * This file is part of HELM, an Hypertextual, Electronic + * Library of Mathematics, developed at the Computer Science + * Department, University of Bologna, Italy. + * + * HELM is free software; you can redistribute it and/or + * modify it under the terms of the GNU General Public License + * as published by the Free Software Foundation; either version 2 + * of the License, or (at your option) any later version. + * + * HELM is distributed in the hope that it will be useful, + * but WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + * GNU General Public License for more details. + * + * You should have received a copy of the GNU General Public License + * along with HELM; if not, write to the Free Software + * Foundation, Inc., 59 Temple Place - Suite 330, Boston, + * MA 02111-1307, USA. + * + * For details, see the HELM World-Wide-Web page, + * http://cs.unibo.it/helm/. + *) + +(* $Id$ *) + +module Index = Equality_indexing.DT (* discrimination tree based indexing *) +(* +module Index = Equality_indexing.DT (* path tree based indexing *) +*) + +let debug_print = Utils.debug_print;; + + +type retrieval_mode = Matching | Unification;; + +let print_candidates mode term res = + let _ = + match mode with + | Matching -> + Printf.printf "| candidates Matching %s\n" (CicPp.ppterm term) + | Unification -> + Printf.printf "| candidates Unification %s\n" (CicPp.ppterm term) + in + print_endline + (String.concat "\n" + (List.map + (fun (p, e) -> + Printf.sprintf "| (%s, %s)" (Utils.string_of_pos p) + (Inference.string_of_equality e)) + res)); + print_endline "|"; +;; + + +let indexing_retrieval_time = ref 0.;; + + +let apply_subst = CicMetaSubst.apply_subst + +let index = Index.index +let remove_index = Index.remove_index +let in_index = Index.in_index +let empty = Index.empty +let init_index = Index.init_index + +(* returns a list of all the equalities in the tree that are in relation + "mode" with the given term, where mode can be either Matching or + Unification. + + Format of the return value: list of tuples in the form: + (position - Left or Right - of the term that matched the given one in this + equality, + equality found) + + Note that if equality is "left = right", if the ordering is left > right, + the position will always be Left, and if the ordering is left < right, + position will be Right. +*) +let get_candidates mode tree term = + let t1 = Unix.gettimeofday () in + let res = + let s = + match mode with + | Matching -> Index.retrieve_generalizations tree term + | Unification -> Index.retrieve_unifiables tree term + in + Index.PosEqSet.elements s + in + (* print_candidates mode term res; *) +(* print_endline (Discrimination_tree.string_of_discrimination_tree tree); *) +(* print_newline (); *) + let t2 = Unix.gettimeofday () in + indexing_retrieval_time := !indexing_retrieval_time +. (t2 -. t1); + res +;; + + +let match_unif_time_ok = ref 0.;; +let match_unif_time_no = ref 0.;; + + +(* + finds the first equality in the index that matches "term", of type "termty" + termty can be Implicit if it is not needed. The result (one of the sides of + the equality, actually) should be not greater (wrt the term ordering) than + term + + Format of the return value: + + (term to substitute, [Cic.Rel 1 properly lifted - see the various + build_newtarget functions inside the various + demodulation_* functions] + substitution used for the matching, + metasenv, + ugraph, [substitution, metasenv and ugraph have the same meaning as those + returned by CicUnification.fo_unif] + (equality where the matching term was found, [i.e. the equality to use as + rewrite rule] + uri [either eq_ind_URI or eq_ind_r_URI, depending on the direction of + the equality: this is used to build the proof term, again see one of + the build_newtarget functions] + )) +*) +let rec find_matches metasenv context ugraph lift_amount term termty = + let module C = Cic in + let module U = Utils in + let module S = CicSubstitution in + let module M = CicMetaSubst in + let module HL = HelmLibraryObjects in + let cmp = !Utils.compare_terms in + let check = match termty with C.Implicit None -> false | _ -> true in + function + | [] -> None + | candidate::tl -> + let pos, (_, proof, (ty, left, right, o), metas, args) = candidate in + if check && not (fst (CicReduction.are_convertible + ~metasenv context termty ty ugraph)) then ( + find_matches metasenv context ugraph lift_amount term termty tl + ) else + let do_match c eq_URI = + let subst', metasenv', ugraph' = + let t1 = Unix.gettimeofday () in + try + let r = + Inference.matching (metasenv @ metas) context + term (S.lift lift_amount c) ugraph in + let t2 = Unix.gettimeofday () in + match_unif_time_ok := !match_unif_time_ok +. (t2 -. t1); + r + with Inference.MatchingFailure as e -> + let t2 = Unix.gettimeofday () in + match_unif_time_no := !match_unif_time_no +. (t2 -. t1); + raise e + in + Some (C.Rel (1 + lift_amount), subst', metasenv', ugraph', + (candidate, eq_URI)) + in + let c, other, eq_URI = + if pos = Utils.Left then left, right, Utils.eq_ind_URI () + else right, left, Utils.eq_ind_r_URI () + in + if o <> U.Incomparable then + try + do_match c eq_URI + with Inference.MatchingFailure -> + find_matches metasenv context ugraph lift_amount term termty tl + else + let res = + try do_match c eq_URI + with Inference.MatchingFailure -> None + in + match res with + | Some (_, s, _, _, _) -> + let c' = apply_subst s c in + let other' = U.guarded_simpl context (apply_subst s other) in + let order = cmp c' other' in + let names = U.names_of_context context in + if order = U.Gt then + res + else + find_matches + metasenv context ugraph lift_amount term termty tl + | None -> + find_matches metasenv context ugraph lift_amount term termty tl +;; + + +(* + as above, but finds all the matching equalities, and the matching condition + can be either Inference.matching or Inference.unification +*) +let rec find_all_matches ?(unif_fun=Inference.unification) + metasenv context ugraph lift_amount term termty = + let module C = Cic in + let module U = Utils in + let module S = CicSubstitution in + let module M = CicMetaSubst in + let module HL = HelmLibraryObjects in + let cmp = !Utils.compare_terms in + function + | [] -> [] + | candidate::tl -> + let pos, (_, _, (ty, left, right, o), metas, args) = candidate in + let do_match c eq_URI = + let subst', metasenv', ugraph' = + let t1 = Unix.gettimeofday () in + try + let r = + unif_fun (metasenv @ metas) context + term (S.lift lift_amount c) ugraph in + let t2 = Unix.gettimeofday () in + match_unif_time_ok := !match_unif_time_ok +. (t2 -. t1); + r + with + | Inference.MatchingFailure + | CicUnification.UnificationFailure _ + | CicUnification.Uncertain _ as e -> + let t2 = Unix.gettimeofday () in + match_unif_time_no := !match_unif_time_no +. (t2 -. t1); + raise e + in + (C.Rel (1 + lift_amount), subst', metasenv', ugraph', + (candidate, eq_URI)) + in + let c, other, eq_URI = + if pos = Utils.Left then left, right, Utils.eq_ind_URI () + else right, left, Utils.eq_ind_r_URI () + in + if o <> U.Incomparable then + try + let res = do_match c eq_URI in + res::(find_all_matches ~unif_fun metasenv context ugraph + lift_amount term termty tl) + with + | Inference.MatchingFailure + | CicUnification.UnificationFailure _ + | CicUnification.Uncertain _ -> + find_all_matches ~unif_fun metasenv context ugraph + lift_amount term termty tl + else + try + let res = do_match c eq_URI in + match res with + | _, s, _, _, _ -> + let c' = apply_subst s c + and other' = apply_subst s other in + let order = cmp c' other' in + let names = U.names_of_context context in + if order <> U.Lt && order <> U.Le then + res::(find_all_matches ~unif_fun metasenv context ugraph + lift_amount term termty tl) + else + find_all_matches ~unif_fun metasenv context ugraph + lift_amount term termty tl + with + | Inference.MatchingFailure + | CicUnification.UnificationFailure _ + | CicUnification.Uncertain _ -> + find_all_matches ~unif_fun metasenv context ugraph + lift_amount term termty tl +;; + + +(* + returns true if target is subsumed by some equality in table +*) +let subsumption env table target = + let _, _, (ty, left, right, _), tmetas, _ = target in + let metasenv, context, ugraph = env in + let metasenv = metasenv @ tmetas in + let samesubst subst subst' = + let tbl = Hashtbl.create (List.length subst) in + List.iter (fun (m, (c, t1, t2)) -> Hashtbl.add tbl m (c, t1, t2)) subst; + List.for_all + (fun (m, (c, t1, t2)) -> + try + let c', t1', t2' = Hashtbl.find tbl m in + if (c = c') && (t1 = t1') && (t2 = t2') then true + else false + with Not_found -> + true) + subst' + in + let leftr = + match left with + | Cic.Meta _ -> [] + | _ -> + let leftc = get_candidates Matching table left in + find_all_matches ~unif_fun:Inference.matching + metasenv context ugraph 0 left ty leftc + in + let rec ok what = function + | [] -> false, [] + | (_, subst, menv, ug, ((pos, (_, _, (_, l, r, o), m, _)), _))::tl -> + try + let other = if pos = Utils.Left then r else l in + let subst', menv', ug' = + let t1 = Unix.gettimeofday () in + try + let r = + Inference.matching (metasenv @ menv @ m) context what other ugraph + in + let t2 = Unix.gettimeofday () in + match_unif_time_ok := !match_unif_time_ok +. (t2 -. t1); + r + with Inference.MatchingFailure as e -> + let t2 = Unix.gettimeofday () in + match_unif_time_no := !match_unif_time_no +. (t2 -. t1); + raise e + in + if samesubst subst subst' then + true, subst + else + ok what tl + with Inference.MatchingFailure -> + ok what tl + in + let r, subst = ok right leftr in + let r, s = + if r then + true, subst + else + let rightr = + match right with + | Cic.Meta _ -> [] + | _ -> + let rightc = get_candidates Matching table right in + find_all_matches ~unif_fun:Inference.matching + metasenv context ugraph 0 right ty rightc + in + ok left rightr + in +(* (if r then *) +(* debug_print *) +(* (lazy *) +(* (Printf.sprintf "SUBSUMPTION! %s\n%s\n" *) +(* (Inference.string_of_equality target) (Utils.print_subst s)))); *) + r, s +;; + + +let rec demodulation_aux ?(typecheck=false) + metasenv context ugraph table lift_amount term = + let module C = Cic in + let module S = CicSubstitution in + let module M = CicMetaSubst in + let module HL = HelmLibraryObjects in + let candidates = get_candidates Matching table term in + match term with + | C.Meta _ -> None + | term -> + let termty, ugraph = + if typecheck then + CicTypeChecker.type_of_aux' metasenv context term ugraph + else + C.Implicit None, ugraph + in + let res = + find_matches metasenv context ugraph lift_amount term termty candidates + in + if res <> None then + res + else + match term with + | C.Appl l -> + let res, ll = + List.fold_left + (fun (res, tl) t -> + if res <> None then + (res, tl @ [S.lift 1 t]) + else + let r = + demodulation_aux metasenv context ugraph table + lift_amount t + in + match r with + | None -> (None, tl @ [S.lift 1 t]) + | Some (rel, _, _, _, _) -> (r, tl @ [rel])) + (None, []) l + in ( + match res with + | None -> None + | Some (_, subst, menv, ug, eq_found) -> + Some (C.Appl ll, subst, menv, ug, eq_found) + ) + | C.Prod (nn, s, t) -> + let r1 = + demodulation_aux metasenv context ugraph table lift_amount s in ( + match r1 with + | None -> + let r2 = + demodulation_aux metasenv + ((Some (nn, C.Decl s))::context) ugraph + table (lift_amount+1) t + in ( + match r2 with + | None -> None + | Some (t', subst, menv, ug, eq_found) -> + Some (C.Prod (nn, (S.lift 1 s), t'), + subst, menv, ug, eq_found) + ) + | Some (s', subst, menv, ug, eq_found) -> + Some (C.Prod (nn, s', (S.lift 1 t)), + subst, menv, ug, eq_found) + ) + | C.Lambda (nn, s, t) -> + let r1 = + demodulation_aux metasenv context ugraph table lift_amount s in ( + match r1 with + | None -> + let r2 = + demodulation_aux metasenv + ((Some (nn, C.Decl s))::context) ugraph + table (lift_amount+1) t + in ( + match r2 with + | None -> None + | Some (t', subst, menv, ug, eq_found) -> + Some (C.Lambda (nn, (S.lift 1 s), t'), + subst, menv, ug, eq_found) + ) + | Some (s', subst, menv, ug, eq_found) -> + Some (C.Lambda (nn, s', (S.lift 1 t)), + subst, menv, ug, eq_found) + ) + | t -> + None +;; + + +let build_newtarget_time = ref 0.;; + + +let demod_counter = ref 1;; + +(** demodulation, when target is an equality *) +let rec demodulation_equality newmeta env table sign target = + let module C = Cic in + let module S = CicSubstitution in + let module M = CicMetaSubst in + let module HL = HelmLibraryObjects in + let module U = Utils in + let metasenv, context, ugraph = env in + let _, proof, (eq_ty, left, right, order), metas, args = target in + let metasenv' = metasenv @ metas in + + let maxmeta = ref newmeta in + + let build_newtarget is_left (t, subst, menv, ug, (eq_found, eq_URI)) = + let time1 = Unix.gettimeofday () in + + let pos, (_, proof', (ty, what, other, _), menv', args') = eq_found in + let ty = + try fst (CicTypeChecker.type_of_aux' metasenv context what ugraph) + with CicUtil.Meta_not_found _ -> ty + in + let what, other = if pos = Utils.Left then what, other else other, what in + let newterm, newproof = + let bo = U.guarded_simpl context (apply_subst subst (S.subst other t)) in + let name = C.Name ("x_Demod_" ^ (string_of_int !demod_counter)) in + incr demod_counter; + let bo' = + let l, r = if is_left then t, S.lift 1 right else S.lift 1 left, t in + C.Appl [C.MutInd (LibraryObjects.eq_URI (), 0, []); + S.lift 1 eq_ty; l; r] + in + if sign = Utils.Positive then + (bo, + Inference.ProofBlock ( + subst, eq_URI, (name, ty), bo'(* t' *), eq_found, proof)) + else + let metaproof = + incr maxmeta; + let irl = + CicMkImplicit.identity_relocation_list_for_metavariable context in +(* debug_print (lazy (Printf.sprintf "\nADDING META: %d\n" !maxmeta)); *) +(* print_newline (); *) + C.Meta (!maxmeta, irl) + in + let eq_found = + let proof' = + let termlist = + if pos = Utils.Left then [ty; what; other] + else [ty; other; what] + in + Inference.ProofSymBlock (termlist, proof') + in + let what, other = + if pos = Utils.Left then what, other else other, what + in + pos, (0, proof', (ty, other, what, Utils.Incomparable), + menv', args') + in + let target_proof = + let pb = + Inference.ProofBlock (subst, eq_URI, (name, ty), bo', + eq_found, Inference.BasicProof metaproof) + in + match proof with + | Inference.BasicProof _ -> + print_endline "replacing a BasicProof"; + pb + | Inference.ProofGoalBlock (_, parent_proof) -> + print_endline "replacing another ProofGoalBlock"; + Inference.ProofGoalBlock (pb, parent_proof) + | _ -> assert false + in + let refl = + C.Appl [C.MutConstruct (* reflexivity *) + (LibraryObjects.eq_URI (), 0, 1, []); + eq_ty; if is_left then right else left] + in + (bo, + Inference.ProofGoalBlock (Inference.BasicProof refl, target_proof)) + in + let left, right = if is_left then newterm, right else left, newterm in + let m = (Inference.metas_of_term left) @ (Inference.metas_of_term right) in + let newmetasenv = List.filter (fun (i, _, _) -> List.mem i m) metas + and newargs = args + in + let ordering = !Utils.compare_terms left right in + + let time2 = Unix.gettimeofday () in + build_newtarget_time := !build_newtarget_time +. (time2 -. time1); + + let res = + let w = Utils.compute_equality_weight eq_ty left right in + (w, newproof, (eq_ty, left, right, ordering), newmetasenv, newargs) + in + !maxmeta, res + in + let res = demodulation_aux metasenv' context ugraph table 0 left in + let newmeta, newtarget = + match res with + | Some t -> + let newmeta, newtarget = build_newtarget true t in + if (Inference.is_identity (metasenv', context, ugraph) newtarget) || + (Inference.meta_convertibility_eq target newtarget) then + newmeta, newtarget + else + demodulation_equality newmeta env table sign newtarget + | None -> + let res = demodulation_aux metasenv' context ugraph table 0 right in + match res with + | Some t -> + let newmeta, newtarget = build_newtarget false t in + if (Inference.is_identity (metasenv', context, ugraph) newtarget) || + (Inference.meta_convertibility_eq target newtarget) then + newmeta, newtarget + else + demodulation_equality newmeta env table sign newtarget + | None -> + newmeta, target + in + (* newmeta, newtarget *) + (* tentiamo di ridurre usando CicReduction.normalize *) + let w, p, (ty, left, right, o), m, a = newtarget in + let left' = ProofEngineReduction.simpl context left in + let right' = ProofEngineReduction.simpl context right in + let newleft = + if !Utils.compare_terms left' left = Utils.Lt then left' else left in + let newright = + if !Utils.compare_terms right' right = Utils.Lt then right' else right in +(* if newleft != left || newright != right then ( *) +(* debug_print *) +(* (lazy *) +(* (Printf.sprintf "left: %s, left': %s\nright: %s, right': %s\n" *) +(* (CicPp.ppterm left) (CicPp.ppterm left') (CicPp.ppterm right) *) +(* (CicPp.ppterm right'))) *) +(* ); *) + let w' = Utils.compute_equality_weight ty newleft newright in + let o' = !Utils.compare_terms newleft newright in + newmeta, (w', p, (ty, newleft, newright, o'), m, a) +;; + + +(** + Performs the beta expansion of the term "term" w.r.t. "table", + i.e. returns the list of all the terms t s.t. "(t term) = t2", for some t2 + in table. +*) +let rec betaexpand_term metasenv context ugraph table lift_amount term = + let module C = Cic in + let module S = CicSubstitution in + let module M = CicMetaSubst in + let module HL = HelmLibraryObjects in + let candidates = get_candidates Unification table term in + let res, lifted_term = + match term with + | C.Meta (i, l) -> + let l', lifted_l = + List.fold_right + (fun arg (res, lifted_tl) -> + match arg with + | Some arg -> + let arg_res, lifted_arg = + betaexpand_term metasenv context ugraph table + lift_amount arg in + let l1 = + List.map + (fun (t, s, m, ug, eq_found) -> + (Some t)::lifted_tl, s, m, ug, eq_found) + arg_res + in + (l1 @ + (List.map + (fun (l, s, m, ug, eq_found) -> + (Some lifted_arg)::l, s, m, ug, eq_found) + res), + (Some lifted_arg)::lifted_tl) + | None -> + (List.map + (fun (r, s, m, ug, eq_found) -> + None::r, s, m, ug, eq_found) res, + None::lifted_tl) + ) l ([], []) + in + let e = + List.map + (fun (l, s, m, ug, eq_found) -> + (C.Meta (i, l), s, m, ug, eq_found)) l' + in + e, C.Meta (i, lifted_l) + + | C.Rel m -> + [], if m <= lift_amount then C.Rel m else C.Rel (m+1) + + | C.Prod (nn, s, t) -> + let l1, lifted_s = + betaexpand_term metasenv context ugraph table lift_amount s in + let l2, lifted_t = + betaexpand_term metasenv ((Some (nn, C.Decl s))::context) ugraph + table (lift_amount+1) t in + let l1' = + List.map + (fun (t, s, m, ug, eq_found) -> + C.Prod (nn, t, lifted_t), s, m, ug, eq_found) l1 + and l2' = + List.map + (fun (t, s, m, ug, eq_found) -> + C.Prod (nn, lifted_s, t), s, m, ug, eq_found) l2 in + l1' @ l2', C.Prod (nn, lifted_s, lifted_t) + + | C.Lambda (nn, s, t) -> + let l1, lifted_s = + betaexpand_term metasenv context ugraph table lift_amount s in + let l2, lifted_t = + betaexpand_term metasenv ((Some (nn, C.Decl s))::context) ugraph + table (lift_amount+1) t in + let l1' = + List.map + (fun (t, s, m, ug, eq_found) -> + C.Lambda (nn, t, lifted_t), s, m, ug, eq_found) l1 + and l2' = + List.map + (fun (t, s, m, ug, eq_found) -> + C.Lambda (nn, lifted_s, t), s, m, ug, eq_found) l2 in + l1' @ l2', C.Lambda (nn, lifted_s, lifted_t) + + | C.Appl l -> + let l', lifted_l = + List.fold_right + (fun arg (res, lifted_tl) -> + let arg_res, lifted_arg = + betaexpand_term metasenv context ugraph table lift_amount arg + in + let l1 = + List.map + (fun (a, s, m, ug, eq_found) -> + a::lifted_tl, s, m, ug, eq_found) + arg_res + in + (l1 @ + (List.map + (fun (r, s, m, ug, eq_found) -> + lifted_arg::r, s, m, ug, eq_found) + res), + lifted_arg::lifted_tl) + ) l ([], []) + in + (List.map + (fun (l, s, m, ug, eq_found) -> (C.Appl l, s, m, ug, eq_found)) l', + C.Appl lifted_l) + + | t -> [], (S.lift lift_amount t) + in + match term with + | C.Meta (i, l) -> res, lifted_term + | term -> + let termty, ugraph = + C.Implicit None, ugraph +(* CicTypeChecker.type_of_aux' metasenv context term ugraph *) + in + let r = + find_all_matches + metasenv context ugraph lift_amount term termty candidates + in + r @ res, lifted_term +;; + + +let sup_l_counter = ref 1;; + +(** + superposition_left + returns a list of new clauses inferred with a left superposition step + the negative equation "target" and one of the positive equations in "table" +*) +let superposition_left newmeta (metasenv, context, ugraph) table target = + let module C = Cic in + let module S = CicSubstitution in + let module M = CicMetaSubst in + let module HL = HelmLibraryObjects in + let module CR = CicReduction in + let module U = Utils in + let weight, proof, (eq_ty, left, right, ordering), _, _ = target in + let expansions, _ = + let term = if ordering = U.Gt then left else right in + betaexpand_term metasenv context ugraph table 0 term + in + let maxmeta = ref newmeta in + let build_new (bo, s, m, ug, (eq_found, eq_URI)) = + +(* debug_print (lazy "\nSUPERPOSITION LEFT\n"); *) + + let time1 = Unix.gettimeofday () in + + let pos, (_, proof', (ty, what, other, _), menv', args') = eq_found in + let what, other = if pos = Utils.Left then what, other else other, what in + let newgoal, newproof = + let bo' = U.guarded_simpl context (apply_subst s (S.subst other bo)) in + let name = C.Name ("x_SupL_" ^ (string_of_int !sup_l_counter)) in + incr sup_l_counter; + let bo'' = + let l, r = + if ordering = U.Gt then bo, S.lift 1 right else S.lift 1 left, bo in + C.Appl [C.MutInd (LibraryObjects.eq_URI (), 0, []); + S.lift 1 eq_ty; l; r] + in + incr maxmeta; + let metaproof = + let irl = + CicMkImplicit.identity_relocation_list_for_metavariable context in + C.Meta (!maxmeta, irl) + in + let eq_found = + let proof' = + let termlist = + if pos = Utils.Left then [ty; what; other] + else [ty; other; what] + in + Inference.ProofSymBlock (termlist, proof') + in + let what, other = + if pos = Utils.Left then what, other else other, what + in + pos, (0, proof', (ty, other, what, Utils.Incomparable), menv', args') + in + let target_proof = + let pb = + Inference.ProofBlock (s, eq_URI, (name, ty), bo'', eq_found, + Inference.BasicProof metaproof) + in + match proof with + | Inference.BasicProof _ -> +(* debug_print (lazy "replacing a BasicProof"); *) + pb + | Inference.ProofGoalBlock (_, parent_proof) -> +(* debug_print (lazy "replacing another ProofGoalBlock"); *) + Inference.ProofGoalBlock (pb, parent_proof) + | _ -> assert false + in + let refl = + C.Appl [C.MutConstruct (* reflexivity *) + (LibraryObjects.eq_URI (), 0, 1, []); + eq_ty; if ordering = U.Gt then right else left] + in + (bo', + Inference.ProofGoalBlock (Inference.BasicProof refl, target_proof)) + in + let left, right = + if ordering = U.Gt then newgoal, right else left, newgoal in + let neworder = !Utils.compare_terms left right in + + let time2 = Unix.gettimeofday () in + build_newtarget_time := !build_newtarget_time +. (time2 -. time1); + + let res = + let w = Utils.compute_equality_weight eq_ty left right in + (w, newproof, (eq_ty, left, right, neworder), [], []) + in + res + in + !maxmeta, List.map build_new expansions +;; + + +let sup_r_counter = ref 1;; + +(** + superposition_right + returns a list of new clauses inferred with a right superposition step + between the positive equation "target" and one in the "table" "newmeta" is + the first free meta index, i.e. the first number above the highest meta + index: its updated value is also returned +*) +let superposition_right newmeta (metasenv, context, ugraph) table target = + let module C = Cic in + let module S = CicSubstitution in + let module M = CicMetaSubst in + let module HL = HelmLibraryObjects in + let module CR = CicReduction in + let module U = Utils in + let _, eqproof, (eq_ty, left, right, ordering), newmetas, args = target in + let metasenv' = metasenv @ newmetas in + let maxmeta = ref newmeta in + let res1, res2 = + match ordering with + | U.Gt -> fst (betaexpand_term metasenv' context ugraph table 0 left), [] + | U.Lt -> [], fst (betaexpand_term metasenv' context ugraph table 0 right) + | _ -> + let res l r = + List.filter + (fun (_, subst, _, _, _) -> + let subst = apply_subst subst in + let o = !Utils.compare_terms (subst l) (subst r) in + o <> U.Lt && o <> U.Le) + (fst (betaexpand_term metasenv' context ugraph table 0 l)) + in + (res left right), (res right left) + in + let build_new ordering (bo, s, m, ug, (eq_found, eq_URI)) = + + let time1 = Unix.gettimeofday () in + + let pos, (_, proof', (ty, what, other, _), menv', args') = eq_found in + let what, other = if pos = Utils.Left then what, other else other, what in + let newgoal, newproof = + let bo' = apply_subst s (S.subst other bo) in + let t' = + let name = C.Name ("x_SupR_" ^ (string_of_int !sup_r_counter)) in + incr sup_r_counter; + let l, r = + if ordering = U.Gt then bo, S.lift 1 right else S.lift 1 left, bo in + (name, ty, S.lift 1 eq_ty, l, r) + in + let name = C.Name ("x_SupR_" ^ (string_of_int !sup_r_counter)) in + incr sup_r_counter; + let bo'' = + let l, r = + if ordering = U.Gt then bo, S.lift 1 right else S.lift 1 left, bo in + C.Appl [C.MutInd (LibraryObjects.eq_URI (), 0, []); + S.lift 1 eq_ty; l; r] + in + bo', + Inference.ProofBlock (s, eq_URI, (name, ty), bo'', eq_found, eqproof) + in + let newmeta, newequality = + let left, right = + if ordering = U.Gt then newgoal, apply_subst s right + else apply_subst s left, newgoal in + let neworder = !Utils.compare_terms left right + and newmenv = newmetas @ menv' + and newargs = args @ args' in + let eq' = + let w = Utils.compute_equality_weight eq_ty left right in + (w, newproof, (eq_ty, left, right, neworder), newmenv, newargs) + and env = (metasenv, context, ugraph) in + let newm, eq' = Inference.fix_metas !maxmeta eq' in + newm, eq' + in + maxmeta := newmeta; + + let time2 = Unix.gettimeofday () in + build_newtarget_time := !build_newtarget_time +. (time2 -. time1); + + newequality + in + let new1 = List.map (build_new U.Gt) res1 + and new2 = List.map (build_new U.Lt) res2 in + let ok e = not (Inference.is_identity (metasenv, context, ugraph) e) in + (!maxmeta, + (List.filter ok (new1 @ new2))) +;; + + +(** demodulation, when the target is a goal *) +let rec demodulation_goal newmeta env table goal = + let module C = Cic in + let module S = CicSubstitution in + let module M = CicMetaSubst in + let module HL = HelmLibraryObjects in + let metasenv, context, ugraph = env in + let maxmeta = ref newmeta in + let proof, metas, term = goal in + let metasenv' = metasenv @ metas in + + let build_newgoal (t, subst, menv, ug, (eq_found, eq_URI)) = + let pos, (_, proof', (ty, what, other, _), menv', args') = eq_found in + let what, other = if pos = Utils.Left then what, other else other, what in + let ty = + try fst (CicTypeChecker.type_of_aux' metasenv context what ugraph) + with CicUtil.Meta_not_found _ -> ty + in + let newterm, newproof = + let bo = apply_subst subst (S.subst other t) in + let bo' = apply_subst subst t in + let name = C.Name ("x_DemodGoal_" ^ (string_of_int !demod_counter)) in + incr demod_counter; + let metaproof = + incr maxmeta; + let irl = + CicMkImplicit.identity_relocation_list_for_metavariable context in +(* debug_print (lazy (Printf.sprintf "\nADDING META: %d\n" !maxmeta)); *) + C.Meta (!maxmeta, irl) + in + let eq_found = + let proof' = + let termlist = + if pos = Utils.Left then [ty; what; other] + else [ty; other; what] + in + Inference.ProofSymBlock (termlist, proof') + in + let what, other = + if pos = Utils.Left then what, other else other, what + in + pos, (0, proof', (ty, other, what, Utils.Incomparable), menv', args') + in + let goal_proof = + let pb = + Inference.ProofBlock (subst, eq_URI, (name, ty), bo', + eq_found, Inference.BasicProof metaproof) + in + let rec repl = function + | Inference.NoProof -> +(* debug_print (lazy "replacing a NoProof"); *) + pb + | Inference.BasicProof _ -> +(* debug_print (lazy "replacing a BasicProof"); *) + pb + | Inference.ProofGoalBlock (_, parent_proof) -> +(* debug_print (lazy "replacing another ProofGoalBlock"); *) + Inference.ProofGoalBlock (pb, parent_proof) + | (Inference.SubProof (term, meta_index, p) as subproof) -> +(* debug_print *) +(* (lazy *) +(* (Printf.sprintf "replacing %s" *) +(* (Inference.string_of_proof subproof))); *) + Inference.SubProof (term, meta_index, repl p) + | _ -> assert false + in repl proof + in + bo, Inference.ProofGoalBlock (Inference.NoProof, goal_proof) + in + let m = Inference.metas_of_term newterm in + let newmetasenv = List.filter (fun (i, _, _) -> List.mem i m) metas in + !maxmeta, (newproof, newmetasenv, newterm) + in + let res = + demodulation_aux ~typecheck:true metasenv' context ugraph table 0 term + in + match res with + | Some t -> + let newmeta, newgoal = build_newgoal t in + let _, _, newg = newgoal in + if Inference.meta_convertibility term newg then + newmeta, newgoal + else + demodulation_goal newmeta env table newgoal + | None -> + newmeta, goal +;; + + +(** demodulation, when the target is a theorem *) +let rec demodulation_theorem newmeta env table theorem = + let module C = Cic in + let module S = CicSubstitution in + let module M = CicMetaSubst in + let module HL = HelmLibraryObjects in + let metasenv, context, ugraph = env in + let maxmeta = ref newmeta in + let proof, metas, term = theorem in + let term, termty, metas = theorem in + let metasenv' = metasenv @ metas in + + let build_newtheorem (t, subst, menv, ug, (eq_found, eq_URI)) = + let pos, (_, proof', (ty, what, other, _), menv', args') = eq_found in + let what, other = if pos = Utils.Left then what, other else other, what in + let newterm, newty = + let bo = apply_subst subst (S.subst other t) in + let bo' = apply_subst subst t in + let name = C.Name ("x_DemodThm_" ^ (string_of_int !demod_counter)) in + incr demod_counter; + let newproof = + Inference.ProofBlock (subst, eq_URI, (name, ty), bo', eq_found, + Inference.BasicProof term) + in + (Inference.build_proof_term newproof, bo) + in + let m = Inference.metas_of_term newterm in + let newmetasenv = List.filter (fun (i, _, _) -> List.mem i m) metas in + !maxmeta, (newterm, newty, newmetasenv) + in + let res = + demodulation_aux ~typecheck:true metasenv' context ugraph table 0 termty + in + match res with + | Some t -> + let newmeta, newthm = build_newtheorem t in + let newt, newty, _ = newthm in + if Inference.meta_convertibility termty newty then + newmeta, newthm + else + demodulation_theorem newmeta env table newthm + | None -> + newmeta, theorem +;;