+(* Copyright (C) 2000, 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/.
+ *)
+
+open ProofEngineHelpers
+open ProofEngineTypes
+
+ (* proof assistant status *)
+
+let proof = ref (None : proof option)
+let goal = ref (None : goal option)
+
+let get_proof () = !proof;;
+let set_proof p = proof := p;;
+
+let get_current_status_as_xml () =
+ match get_proof () with
+ None -> assert false
+ | Some (uri, metasenv, bo, ty) ->
+ let uri = match uri with Some uri -> uri | None -> assert false in
+ let currentproof =
+ (*CSC: Wrong: [] is just plainly wrong *)
+ Cic.CurrentProof (UriManager.name_of_uri uri,metasenv,bo,ty,[])
+ in
+ let (acurrentproof,_,_,ids_to_inner_sorts,_,_,_) =
+ Cic2acic.acic_object_of_cic_object ~eta_fix:false currentproof
+ in
+ let xml, bodyxml =
+ match
+ Cic2Xml.print_object uri ~ids_to_inner_sorts
+ ~ask_dtd_to_the_getter:true acurrentproof
+ with
+ xml,Some bodyxml -> xml,bodyxml
+ | _,None -> assert false
+ in
+ (xml, bodyxml)
+;;
+
+let apply_tactic ~tactic =
+ let module PET = ProofEngineTypes in
+ match get_proof (),!goal with
+ | None,_
+ | _,None -> assert false
+ | Some proof', Some goal' ->
+ let (newproof, newgoals) = PET.apply_tactic tactic (proof', goal') in
+ set_proof (Some newproof);
+ goal :=
+ (match newgoals, newproof with
+ goal::_, _ -> Some goal
+ | [], (_,(goal,_,_)::_,_,_) ->
+ (* the tactic left no open goal ; let's choose the first open goal *)
+ (*CSC: here we could implement and use a proof-tree like notion... *)
+ Some goal
+ | _, _ -> None)
+;;
+
+(* metas_in_term term *)
+(* Returns the ordered list of the metas that occur in [term]. *)
+(* Duplicates are removed. The implementation is not very efficient. *)
+let metas_in_term term =
+ let module C = Cic in
+ let rec aux =
+ function
+ C.Rel _ -> []
+ | C.Meta (n,_) -> [n]
+ | C.Sort _
+ | C.Implicit _ -> []
+ | C.Cast (te,ty) -> (aux te) @ (aux ty)
+ | C.Prod (_,s,t) -> (aux s) @ (aux t)
+ | C.Lambda (_,s,t) -> (aux s) @ (aux t)
+ | C.LetIn (_,s,t) -> (aux s) @ (aux t)
+ | C.Appl l -> List.fold_left (fun i t -> i @ (aux t)) [] l
+ | C.Var (_,exp_named_subst)
+ | C.Const (_,exp_named_subst)
+ | C.MutInd (_,_,exp_named_subst)
+ | C.MutConstruct (_,_,_,exp_named_subst) ->
+ List.fold_left (fun i (_,t) -> i @ (aux t)) [] exp_named_subst
+ | C.MutCase (_,_,outt,t,pl) ->
+ (aux outt) @ (aux t) @
+ (List.fold_left (fun i t -> i @ (aux t)) [] pl)
+ | C.Fix (_,fl) ->
+ List.fold_left (fun i (_,_,ty,bo) -> i @ (aux bo) @ (aux ty)) [] fl
+ | C.CoFix (_,fl) ->
+ List.fold_left (fun i (_,ty,bo) -> i @ (aux bo) @ (aux ty)) [] fl
+ in
+ let metas = aux term in
+ let rec elim_duplicates =
+ function
+ [] -> []
+ | he::tl ->
+ he::(elim_duplicates (List.filter (function el -> he <> el) tl))
+ in
+ elim_duplicates metas
+
+(* perforate context term ty *)
+(* replaces the term [term] in the proof with a new metavariable whose type *)
+(* is [ty]. [context] must be the context of [term] in the whole proof. This *)
+(* could be easily computed; so the only reasons to have it as an argument *)
+(* are efficiency reasons. *)
+let perforate context term ty =
+ let module C = Cic in
+ match get_proof () with
+ None -> assert false
+ | Some (uri,metasenv,bo,gty as proof') ->
+ let newmeta = new_meta_of_proof proof' in
+ (* We push the new meta at the end of the list for pretty-printing *)
+ (* purposes: in this way metas are ordered. *)
+ let metasenv' = metasenv@[newmeta,context,ty] in
+ let irl =
+ CicMkImplicit.identity_relocation_list_for_metavariable context
+ in
+(*CSC: Bug: se ci sono due term uguali nella prova dovrei bucarne uno solo!!!*)
+ let bo' =
+ ProofEngineReduction.replace (==) [term] [C.Meta (newmeta,irl)] bo
+ in
+ (* It may be possible that some metavariables occurred only in *)
+ (* the term we are perforating and they now occurs no more. We *)
+ (* get rid of them, collecting the really useful metavariables *)
+ (* in metasenv''. *)
+(*CSC: Bug: una meta potrebbe non comparire in bo', ma comparire nel tipo *)
+(*CSC: di una metavariabile che compare in bo'!!!!!!! *)
+ let newmetas = metas_in_term bo' in
+ let metasenv'' =
+ List.filter (function (n,_,_) -> List.mem n newmetas) metasenv'
+ in
+ set_proof (Some (uri,metasenv'',bo',gty)) ;
+ goal := Some newmeta
+
+
+(************************************************************)
+(* Some easy tactics. *)
+(************************************************************)
+
+(* Reduces [term] using [reduction_function] in the current scratch goal [ty] *)
+let reduction_tactic_in_scratch reduction_function terms ty =
+ let metasenv =
+ match get_proof () with
+ None -> []
+ | Some (_,metasenv,_,_) -> metasenv
+ in
+ let metano,context,_ =
+ match !goal with
+ None -> assert false
+ | Some metano -> List.find (function (m,_,_) -> m=metano) metasenv
+ in
+ let terms' = List.map (reduction_function context) terms in
+ ProofEngineReduction.replace
+ ~equality:(==) ~what:terms ~with_what:terms' ~where:ty