X-Git-Url: http://matita.cs.unibo.it/gitweb/?p=helm.git;a=blobdiff_plain;f=components%2Ftactics%2Finversion.ml;fp=components%2Ftactics%2Finversion.ml;h=e610212440ac9e71840859f2c76dccf14330f276;hp=0000000000000000000000000000000000000000;hb=f61af501fb4608cc4fb062a0864c774e677f0d76;hpb=58ae1809c352e71e7b5530dc41e2bfc834e1aef1

diff --git a/components/tactics/inversion.ml b/components/tactics/inversion.ml
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+(* Copyright (C) 2002, 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/.
+ *)
+
+(* $Id$ *)
+
+exception TheTypeOfTheCurrentGoalIsAMetaICannotChooseTheRightElimiantionPrinciple
+exception NotAnInductiveTypeToEliminate
+
+let debug = false;; 
+let debug_print =
+ fun msg -> if debug then prerr_endline (Lazy.force msg) else ()
+
+
+let inside_obj = function
+ | Cic.InductiveDefinition (type_list,params, nleft, _) ->
+  (type_list,params,nleft)
+ | _ -> raise (Invalid_argument "Errore in inside_obj")
+
+let term_to_list = function
+ | Cic.Appl l -> l
+ | _ -> raise (Invalid_argument "Errore in term_to_list")
+
+
+let rec baseuri_of_term = function
+ | Cic.Appl l -> baseuri_of_term (List.hd l)  
+ | Cic.MutInd (baseuri, tyno, []) -> baseuri
+ | _ -> raise (Invalid_argument "baseuri_of_term")
+
+(* returns DX1 = DX1 -> ... DXn=DXn -> GOALTY *)
+let rec foo_cut nleft parameters parameters_ty body uri_of_eq = 
+ if nleft > 0 
+ then 
+  foo_cut (nleft-1) (List.tl parameters)  (List.tl parameters_ty) body 
+   uri_of_eq
+ else
+  match parameters with
+   | hd::tl -> 
+    Cic.Prod (
+     Cic.Anonymous, 
+     Cic.Appl[Cic.MutInd (uri_of_eq  ,0,[]);
+      (List.hd parameters_ty) ; hd; hd], 
+     foo_cut nleft (List.map (CicSubstitution.lift 1) tl) 
+      (List.map (CicSubstitution.lift 1) (List.tl parameters_ty)) 
+      (CicSubstitution.lift 1 body) uri_of_eq )
+   | [] -> body
+;;
+
+(* from a complex Cic.Prod term, return the list of its components *)
+let rec get_sort_type term =
+ match term with 
+  | Cic.Prod (_,src,tgt) -> (get_sort_type tgt)
+  | _ -> term
+;;
+
+
+let rec cut_first n l =
+ if n>0 then  
+  match l with
+   | hd::tl -> cut_first (n-1) tl
+   | [] -> []
+ else l
+;;
+
+
+let rec cut_last l =
+ match l with
+  | hd::tl when tl != [] -> hd:: (cut_last tl)
+  | _ -> []
+;;
+
+(* returns the term to apply*)
+let foo_appl nleft nright_consno term uri =
+ let l = [] in
+ let a = ref l in
+ for n = 1 to nleft do
+	a := !a @ [(Cic.Implicit None)]
+ done;
+ a:= !a @ [term];
+ for n = 1 to nright_consno do
+	a := !a @ [(Cic.Implicit None)] 
+ done;
+ (*  apply     i_ind           ? ... ?    H *)
+ Cic.Appl ([Cic.Const(uri,[])] @ !a @ [Cic.Rel 1])
+;;
+
+
+let rec foo_prod nright right_param_tys rightparameters l2 base_rel goalty 
+ uri_of_eq rightparameters_ termty isSetType term =
+  match right_param_tys with
+   | hd::tl -> Cic.Prod (
+    Cic.Anonymous, 
+    Cic.Appl
+     [Cic.MutInd(uri_of_eq,0,[]); hd; (List.hd rightparameters); 
+     Cic.Rel base_rel],
+    foo_prod (nright-1) 
+     (List.map (CicSubstitution.lift 1) tl) 
+     (List.map (CicSubstitution.lift 1) (List.tl rightparameters)) 
+     (List.map (CicSubstitution.lift 1) l2) 
+     base_rel (CicSubstitution.lift 1 goalty) uri_of_eq
+     (List.map (CicSubstitution.lift 1) rightparameters_) 
+     (CicSubstitution.lift 1 termty)
+     isSetType (CicSubstitution.lift 1 term))
+   | [] -> ProofEngineReduction.replace_lifting 
+    ~equality:(fun _ -> CicUtil.alpha_equivalence)
+    ~context:[]
+    ~what: (if isSetType
+     then (rightparameters_ @ [term] ) 
+     else (rightparameters_ ) )
+    ~with_what: (List.map (CicSubstitution.lift (-1)) l2)
+    ~where:goalty 
+(* the same subterm of goalty could be simultaneously sx and dx!*)
+;;
+
+let rec foo_lambda nright right_param_tys nright_ right_param_tys_ 
+ rightparameters created_vars base_rel goalty uri_of_eq rightparameters_ 
+ termty isSetType term =
+  match right_param_tys with
+   | hd::tl -> Cic.Lambda (
+    (Cic.Name ("lambda" ^ (string_of_int nright))),
+    hd, (* type *)
+    foo_lambda (nright-1) 
+     (List.map (CicSubstitution.lift 1) tl) nright_ 
+     (List.map (CicSubstitution.lift 1) right_param_tys_)
+     (List.map (CicSubstitution.lift 1) rightparameters) 
+     (List.map (CicSubstitution.lift 1) (created_vars @ [Cic.Rel 1])) 
+     base_rel (CicSubstitution.lift 1 goalty) uri_of_eq
+     (List.map (CicSubstitution.lift 1) rightparameters_) 
+     (CicSubstitution.lift 1 termty) isSetType
+     (CicSubstitution.lift 1 term)) 
+   | [] when isSetType -> Cic.Lambda (
+    (Cic.Name ("lambda" ^ (string_of_int nright))),
+    (ProofEngineReduction.replace_lifting
+     ~equality:(fun _ -> CicUtil.alpha_equivalence)
+     ~context:[]
+     ~what: (rightparameters_ ) 
+     ~with_what: (List.map (CicSubstitution.lift (-1)) created_vars)
+     ~where:termty), (* type of H with replaced right parameters *)
+    foo_prod nright_ (List.map (CicSubstitution.lift 1) right_param_tys_) 
+     (List.map (CicSubstitution.lift 1) rightparameters)  
+     (List.map (CicSubstitution.lift 1) (created_vars @ [Cic.Rel 1])) 
+     (base_rel+1) (CicSubstitution.lift 1 goalty) uri_of_eq
+     (List.map (CicSubstitution.lift 1) rightparameters_) 
+     (CicSubstitution.lift 1 termty) isSetType
+     (CicSubstitution.lift 1 term))
+   | [] -> foo_prod nright_ right_param_tys_ rightparameters created_vars 
+   base_rel goalty uri_of_eq rightparameters_ 
+    termty isSetType term
+;;
+
+let isSetType paramty = ((Pervasives.compare 
+  (get_sort_type paramty)
+  (Cic.Sort Cic.Prop)) != 0) 
+
+exception EqualityNotDefinedYet
+let private_inversion_tac ~term =
+ let module T = CicTypeChecker in
+ let module R = CicReduction in
+ let module C = Cic in
+ let module P = PrimitiveTactics in
+ let module PET = ProofEngineTypes in
+ let private_inversion_tac ~term (proof, goal) =
+ 
+ (*DEBUG*) debug_print (lazy  ("private inversion begins"));
+ let _,metasenv,_subst,_,_, _ = proof in
+ let uri_of_eq =
+  match LibraryObjects.eq_URI () with
+     None -> raise EqualityNotDefinedYet
+  | Some uri -> uri
+ in
+ let (_,context,goalty) = CicUtil.lookup_meta goal metasenv in
+ let termty,_ = T.type_of_aux' metasenv context term CicUniv.empty_ugraph in
+ let uri = baseuri_of_term termty in  
+ let o,_ = CicEnvironment.get_obj CicUniv.empty_ugraph uri in
+ let (_,_,typeno,_) =
+  match termty with
+   C.MutInd (uri,typeno,exp_named_subst) -> (uri,exp_named_subst,typeno,[])
+   | C.Appl ((C.MutInd (uri,typeno,exp_named_subst))::args) ->
+    (uri,exp_named_subst,typeno,args)
+   | _ -> raise NotAnInductiveTypeToEliminate
+ in
+ let buri = UriManager.buri_of_uri uri in
+ let name,nleft,paramty,cons_list =
+  match o with
+   C.InductiveDefinition (tys,_,nleft,_) ->
+    let (name,_,paramty,cons_list) = List.nth tys typeno in
+    (name,nleft,paramty,cons_list)
+   |_ -> assert false
+ in
+ let eliminator_uri = 
+  UriManager.uri_of_string (buri ^ "/" ^ name ^ "_ind" ^ ".con") 
+ in
+ let parameters = (List.tl (term_to_list termty)) in
+ let parameters_tys =  
+  (List.map 
+   (fun t -> (
+    match (T.type_of_aux' metasenv context t CicUniv.empty_ugraph) with
+     (term,graph) -> term))
+   parameters) 
+ in
+ let consno = List.length cons_list in
+ let nright= ((List.length parameters)- nleft) in 
+ let isSetType = isSetType paramty in
+ let cut_term = foo_cut nleft parameters 
+  parameters_tys goalty uri_of_eq in
+ (*DEBUG*)  debug_print (lazy ("cut term " ^ CicPp.ppterm cut_term));
+  debug_print (lazy ("CONTEXT before apply HCUT: " ^ 
+   (CicMetaSubst.ppcontext ~metasenv [] context )));
+  debug_print (lazy ("termty " ^ CicPp.ppterm termty));
+ (* cut DXn=DXn \to GOAL *)
+ let proof1,gl1 = PET.apply_tactic (P.cut_tac cut_term) (proof,goal) in
+ (* apply Hcut ; reflexivity  *)
+ let proof2, gl2 = PET.apply_tactic
+  (Tacticals.then_
+   ~start: (P.apply_tac (C.Rel 1)) (* apply Hcut *)
+   ~continuation: (EqualityTactics.reflexivity_tac)
+  ) (proof1, (List.hd gl1))
+ in      
+ (*DEBUG*) debug_print (lazy  ("after apply HCUT;reflexivity 
+  in private inversion"));
+ (* apply (ledx_ind( lambda x. lambda y, ...)) *)
+ let t1,metasenv,_subst,t3,t4, attrs = proof2 in
+ let goal2 = List.hd (List.tl gl1) in
+ let (_,context,_) = CicUtil.lookup_meta goal2 metasenv in
+ (* rightparameters type list *)
+ let rightparam_ty_l = (cut_first nleft parameters_tys) in
+ (* rightparameters list *)
+ let rightparameters= cut_first nleft parameters in
+ let lambda_t = foo_lambda nright rightparam_ty_l nright rightparam_ty_l 
+ rightparameters [] nright goalty uri_of_eq rightparameters termty isSetType
+ term in 
+ let t = foo_appl nleft (nright+consno) lambda_t eliminator_uri in
+ debug_print (lazy ("Lambda_t: " ^ (CicPp.ppterm t)));
+ debug_print (lazy ("Term: " ^ (CicPp.ppterm termty)));
+ debug_print (lazy ("Body: " ^ (CicPp.ppterm goalty)));
+ debug_print 
+  (lazy ("Right param: " ^ (CicPp.ppterm (Cic.Appl rightparameters))));
+ debug_print (lazy ("CONTEXT before refinement: " ^ 
+  (CicMetaSubst.ppcontext ~metasenv [] context )));
+  (*DEBUG*) debug_print (lazy  ("private inversion: term before refinement: " ^ 
+   CicPp.ppterm t));
+ let (ref_t,_,metasenv'',_) = CicRefine.type_of_aux' metasenv context t 
+  CicUniv.empty_ugraph 
+ in
+ (*DEBUG*) debug_print (lazy  ("private inversion: termine after refinement: "
+  ^ CicPp.ppterm ref_t));
+ let proof2 = (t1,metasenv'',_subst,t3,t4, attrs) in
+ let my_apply_tac =
+  let my_apply_tac status =
+   let proof,goals = 
+    ProofEngineTypes.apply_tactic (P.apply_tac ref_t) status in
+   let patched_new_goals =
+    let (_,metasenv''',_subst,_,_, _) = proof in
+    let new_goals = ProofEngineHelpers.compare_metasenvs
+     ~oldmetasenv:metasenv ~newmetasenv:metasenv''
+    in
+    List.filter (function i -> List.exists (function (j,_,_) -> j=i) 
+     metasenv''') new_goals @ goals
+   in
+   proof,patched_new_goals
+  in
+ ProofEngineTypes.mk_tactic my_apply_tac
+ in
+ let proof3,gl3 = 
+ PET.apply_tactic
+  (Tacticals.then_
+   ~start:my_apply_tac   
+   ~continuation: 
+    (ReductionTactics.simpl_tac (ProofEngineTypes.conclusion_pattern(None)))) 
+    (proof2,goal2) 
+ in
+
+ (proof3, gl3)
+in	
+ProofEngineTypes.mk_tactic (private_inversion_tac ~term)
+;;
+
+
+let inversion_tac ~term =
+ let module T = CicTypeChecker in
+ let module R = CicReduction in
+ let module C = Cic in
+ let module P = PrimitiveTactics in
+ let module PET = ProofEngineTypes in
+ let inversion_tac ~term (proof, goal) =
+ (*DEBUG*) debug_print (lazy ("inversion begins"));
+  let _,metasenv,_subst,_,_, _ = proof in
+  let (_,context,goalty) = CicUtil.lookup_meta goal metasenv in
+  let termty,_ = T.type_of_aux' metasenv context term CicUniv.empty_ugraph in
+  let uri, typeno = 
+    match termty with
+      | Cic.MutInd (uri,typeno,_) 
+      | Cic.Appl(Cic.MutInd (uri,typeno,_)::_) -> uri,typeno
+      | _ -> assert false
+  in
+  (* let uri = baseuri_of_term termty in *)
+  let obj,_ = CicEnvironment.get_obj CicUniv.empty_ugraph uri in
+  let name,nleft,arity,cons_list =
+   match obj with
+    Cic.InductiveDefinition (tys,_,nleft,_) ->
+     let (name,_,arity,cons_list) = List.nth tys typeno in 
+        (name,nleft,arity,cons_list)
+   |_ -> assert false
+  in
+  let buri = UriManager.buri_of_uri uri in
+  let inversor_uri = 
+   UriManager.uri_of_string (buri ^ "/" ^ name ^ "_inv" ^ ".con") in
+  (* arity length = number  of parameters plus 1 *)
+  let arity_length = (List.length (term_to_list termty)) in
+  (* Check the existence of any right parameter. *)
+  assert (arity_length > (nleft + 1));
+  let appl_term arity_consno uri =
+   let l = [] in
+   let a = ref l in
+   for n = 1 to arity_consno do
+    a := (Cic.Implicit None)::(!a)
+   done;
+   (* apply    i_inv             ? ...?      H).     *)
+   Cic.Appl ([Cic.Const(uri,[])] @ !a @ [term])
+  in
+  let t = appl_term (arity_length + (List.length cons_list)) inversor_uri in
+  let (t1,metasenv,_subst,t3,t4, attrs) = proof in
+  let (ref_t,_,metasenv'',_) = CicRefine.type_of_aux' metasenv context t
+  CicUniv.empty_ugraph 
+  in
+  let proof = (t1,metasenv'',_subst,t3,t4, attrs) in
+  let proof3,gl3 = 
+     ProofEngineTypes.apply_tactic (P.apply_tac ref_t) (proof,goal) in
+  let patched_new_goals =
+     let (_,metasenv''',_subst,_,_, _) = proof3 in
+     let new_goals = ProofEngineHelpers.compare_metasenvs
+      ~oldmetasenv:metasenv ~newmetasenv:metasenv''
+     in
+     List.filter (function i -> List.exists (function (j,_,_) -> j=i) 
+      metasenv''') new_goals @ gl3
+    in
+  (proof3, patched_new_goals)
+ in	
+ProofEngineTypes.mk_tactic (inversion_tac ~term)
+;;