+(* 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/.
+ *)
+
+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