]> matita.cs.unibo.it Git - helm.git/blobdiff - helm/software/components/tactics/discriminationTactics.ml
Injection now clears all intermediate results introduced.
[helm.git] / helm / software / components / tactics / discriminationTactics.ml
index 4c7f5148d1cb5a1ff225c676c7f4ea9931011b01..7c5df0d82eafbbf9bfc7da73ddf573e405e72b12 100644 (file)
@@ -27,7 +27,7 @@
 
 let debug_print = fun _ -> ()
 
-let rec injection_tac ~term =
+let rec injection_tac ~first_time ~term ~liftno ~continuation =
  let injection_tac ~term status = 
   let (proof, goal) = status in
   let module C = Cic in
@@ -36,53 +36,100 @@ let rec injection_tac ~term =
   let module T = Tacticals in
   let _,metasenv,_,_ = proof in
   let _,context,_ = CicUtil.lookup_meta goal metasenv in
+  let term = CicSubstitution.lift liftno term in
   let termty,_ = (* TASSI: FIXME *)
-    CicTypeChecker.type_of_aux' metasenv context term CicUniv.empty_ugraph in  
+    CicTypeChecker.type_of_aux' metasenv context term CicUniv.empty_ugraph
+  in
     ProofEngineTypes.apply_tactic
-      (match termty with
-          (C.Appl [(C.MutInd (equri, 0, [])) ; tty ; t1 ; t2])
-             when LibraryObjects.is_eq_URI equri -> (
+     (match termty with
+         (C.Appl [(C.MutInd (equri, 0, [])) ; tty ; t1 ; t2])
+            when LibraryObjects.is_eq_URI equri ->
+          begin
            match tty with
               (C.MutInd (turi,typeno,exp_named_subst))
-            | (C.Appl (C.MutInd (turi,typeno,exp_named_subst)::_)) -> (
-                   match t1,t2 with
-                      ((C.MutConstruct (uri1,typeno1,consno1,exp_named_subst1)),
-                       (C.MutConstruct (uri2,typeno2,consno2,exp_named_subst2)))
-                         when (uri1 = uri2) && (typeno1 = typeno2) && 
-                             (consno1 = consno2) && (exp_named_subst1 = exp_named_subst2) ->
-                       (* raise (ProofEngineTypes.Fail "Injection: nothing to do") ; *) T.id_tac
-                    | ((C.Appl ((C.MutConstruct (uri1,typeno1,consno1,exp_named_subst1))::applist1)),
-                       (C.Appl ((C.MutConstruct (uri2,typeno2,consno2,exp_named_subst2))::applist2)))
-                         when (uri1 = uri2) && (typeno1 = typeno2) && (consno1 = consno2) && (exp_named_subst1 = exp_named_subst2) ->
-                       let rec traverse_list i l1 l2 =
-                         match l1,l2 with
-                            [],[] -> T.id_tac
-                          | hd1::tl1,hd2::tl2 -> 
-                             T.then_ 
-                              ~start:(injection1_tac ~i ~term)
-                              ~continuation:(traverse_list (i+1) tl1 tl2)
-                          | _ -> raise (ProofEngineTypes.Fail (lazy "Discriminate: i 2 termini hanno in testa lo stesso costruttore, ma applicato a un numero diverso di termini. possibile???"))
-                       in traverse_list 1 applist1 applist2
-                    | ((C.MutConstruct (uri1,typeno1,consno1,exp_named_subst1)),
-                       (C.MutConstruct (uri2,typeno2,consno2,exp_named_subst2)))
-                    | ((C.MutConstruct (uri1,typeno1,consno1,exp_named_subst1)),
-                       (C.Appl ((C.MutConstruct (uri2,typeno2,consno2,exp_named_subst2))::_)))
-                    | ((C.Appl ((C.MutConstruct (uri1,typeno1,consno1,exp_named_subst1))::_)),
-                       (C.MutConstruct (uri2,typeno2,consno2,exp_named_subst2)))
-                    | ((C.Appl ((C.MutConstruct (uri1,typeno1,consno1,exp_named_subst1))::_)),
-                       (C.Appl ((C.MutConstruct (uri2,typeno2,consno2,exp_named_subst2))::_)))
-                         when (consno1 <> consno2) || (exp_named_subst1 <> exp_named_subst2) ->
-                       (* raise (ProofEngineTypes.Fail "Injection: not a projectable equality but a discriminable one") ; *) T.id_tac
-                    | _ -> (* raise (ProofEngineTypes.Fail "Injection: not a projectable equality") ; *) T.id_tac
-                   )
-            | _ -> raise (ProofEngineTypes.Fail (lazy "Injection: not a projectable equality"))
-           )
-        | _ -> raise (ProofEngineTypes.Fail (lazy "Injection: not an equation"))
-      ) status
+            | (C.Appl (C.MutInd (turi,typeno,exp_named_subst)::_)) ->
+               begin
+                match t1,t2 with
+                   ((C.MutConstruct (uri1,typeno1,consno1,exp_named_subst1)),
+                    (C.MutConstruct (uri2,typeno2,consno2,exp_named_subst2)))
+                      when (uri1 = uri2) && (typeno1 = typeno2) && 
+                           (consno1 = consno2) &&
+                    (exp_named_subst1 = exp_named_subst2)
+                   ->
+                    if first_time then
+                     raise
+                      (ProofEngineTypes.Fail (lazy "Injection: nothing to do"))
+                    else
+                     continuation ~liftno
+                 | C.Appl
+                    ((C.MutConstruct
+                       (uri1,typeno1,consno1,exp_named_subst1))::applist1),
+                   C.Appl
+                    ((C.MutConstruct
+                       (uri2,typeno2,consno2,exp_named_subst2))::applist2)
+                      when (uri1 = uri2) && (typeno1 = typeno2) &&
+                       (consno1 = consno2) &&
+                       (exp_named_subst1 = exp_named_subst2)
+                    ->
+                     let rec traverse_list i l1 l2 =
+                       match l1,l2 with
+                          [],[] ->
+                           if first_time then
+                            continuation
+                           else
+                            (match term with
+                                C.Rel n ->
+                                 (match List.nth context (n-1) with
+                                     Some (C.Name id,_) ->
+                                      fun ~liftno ->
+                                       T.then_
+                                        ~start:
+                                          (ProofEngineStructuralRules.clear
+                                            ~hyps:[id])
+                                        ~continuation:(continuation ~liftno)
+                                   | _ -> assert false)
+                              | _ -> assert false)
+                        | hd1::tl1,hd2::tl2 -> 
+                           if
+                            fst
+                             (CicReduction.are_convertible ~metasenv
+                               context hd1 hd2 CicUniv.empty_ugraph)
+                           then
+                            traverse_list (i+1) tl1 tl2
+                           else
+                            injection1_tac ~i ~term
+                             ~continuation:(traverse_list (i+1) tl1 tl2)
+                        | _ -> raise (ProofEngineTypes.Fail (lazy "Discriminate: i 2 termini hanno in testa lo stesso costruttore, ma applicato a un numero diverso di termini. possibile???"))
+                     in
+                      traverse_list 1 applist1 applist2 ~liftno
+                 | ((C.MutConstruct (uri1,typeno1,consno1,exp_named_subst1)),
+                    (C.MutConstruct (uri2,typeno2,consno2,exp_named_subst2)))
+                 | ((C.MutConstruct (uri1,typeno1,consno1,exp_named_subst1)),
+                    (C.Appl ((C.MutConstruct (uri2,typeno2,consno2,exp_named_subst2))::_)))
+                 | ((C.Appl ((C.MutConstruct (uri1,typeno1,consno1,exp_named_subst1))::_)),
+                    (C.MutConstruct (uri2,typeno2,consno2,exp_named_subst2)))
+                 | ((C.Appl ((C.MutConstruct (uri1,typeno1,consno1,exp_named_subst1))::_)),
+                    (C.Appl ((C.MutConstruct (uri2,typeno2,consno2,exp_named_subst2))::_)))
+                      when (consno1 <> consno2) || (exp_named_subst1 <> exp_named_subst2) ->
+                    raise (ProofEngineTypes.Fail (lazy "Injection: not a projectable equality but a discriminable one"))
+                 | _ ->
+                   if first_time then
+                    raise (ProofEngineTypes.Fail (lazy "Injection: not a projectable equality"))
+                   else
+                    continuation ~liftno 
+               end
+            | _ ->
+              if first_time then
+               raise (ProofEngineTypes.Fail (lazy "Injection: not a projectable equality"))
+              else
+               continuation ~liftno 
+           end
+       | _ -> raise (ProofEngineTypes.Fail (lazy "Injection: not an equation"))
+     ) status
  in 
   ProofEngineTypes.mk_tactic (injection_tac ~term)
 
-and injection1_tac ~term ~i 
+and injection1_tac ~term ~i ~liftno ~continuation =
  let injection1_tac ~term ~i status =
   let (proof, goal) = status in
   (* precondizione: t1 e t2 hanno in testa lo stesso costruttore ma differiscono (o potrebbero differire?) nell'i-esimo parametro del costruttore *)
@@ -91,10 +138,12 @@ and injection1_tac ~term ~i =
    let module U = UriManager in
    let module P = PrimitiveTactics in
    let module T = Tacticals in
+   let term = CicSubstitution.lift liftno term in
    let _,metasenv,_,_ = proof in
    let _,context,_ = CicUtil.lookup_meta goal metasenv in
    let termty,_ = (* TASSI: FIXME *)
-     CicTypeChecker.type_of_aux' metasenv context term CicUniv.empty_ugraph in
+     CicTypeChecker.type_of_aux' metasenv context term CicUniv.empty_ugraph
+   in
      match termty with (* an equality *)
          (C.Appl [(C.MutInd (equri, 0, [])) ; tty ; t1 ; t2])
              when LibraryObjects.is_eq_URI equri -> (
@@ -112,90 +161,151 @@ and injection1_tac ~term ~i =
                 let tty',_ = 
                  CicTypeChecker.type_of_aux' metasenv context t1' 
                    CicUniv.empty_ugraph  in
-                let pattern =
-                      match fst(CicEnvironment.get_obj 
-                                 CicUniv.empty_ugraph turi ) with
-                         C.InductiveDefinition (ind_type_list,_,nr_ind_params_dx,_)  ->
-                          let _,_,_,constructor_list = (List.nth ind_type_list typeno) in
-                           let i_constr_id,_ = List.nth constructor_list (consno - 1) in
-                            List.map
-                             (function (id,cty) ->
-                               let reduced_cty = CicReduction.whd context cty in
-                                let rec aux t k =
-                                 match t with
-                                    C.Prod (_,_,target) when (k <= nr_ind_params_dx) ->
-                                     aux target (k+1)
-                                  | C.Prod (binder,source,target) when (k > nr_ind_params_dx) ->
-                                   let binder' =
-                                      match binder with
-                                         C.Name b -> C.Name b
-                                       | C.Anonymous -> C.Name "y"
-                                     in
-                                      C.Lambda (binder',source,(aux target (k+1)))
-                                  | _ ->
-                                     let nr_param_constr = k - 1 - nr_ind_params_dx in
-                                      if (id = i_constr_id)
-                                       then C.Rel (nr_param_constr - i + 1)
-                                       else S.lift (nr_param_constr + 1) t1' (* + 1 per liftare anche il lambda agguinto esternamente al case *)
-                                in aux reduced_cty 1
-                             )
-                             constructor_list
-                       | _ -> raise (ProofEngineTypes.Fail (lazy "Discriminate: object is not an Inductive Definition: it's imposible"))
+                let patterns,outtype =
+                 match
+                  fst (CicEnvironment.get_obj CicUniv.empty_ugraph turi)
+                 with
+                    C.InductiveDefinition (ind_type_list,_,paramsno,_)->
+                     let _,_,_,constructor_list =
+                      List.nth ind_type_list typeno in
+                     let i_constr_id,_ =
+                      List.nth constructor_list (consno - 1) in
+                     let seed = ref 0 in
+                     let patterns =
+                      List.map
+                       (function (id,cty) ->
+                         let reduced_cty = CicReduction.whd context cty in
+                          let rec aux t k =
+                           match t with
+                              C.Prod (_,_,target) when k <= paramsno ->
+                               aux target (k+1)
+                            | C.Prod (binder,source,target) when k > paramsno ->
+                              let binder' =
+                                match binder with
+                                   C.Name _ -> binder
+                                 | C.Anonymous ->
+                                    C.Name
+                                     (incr seed; "y" ^ string_of_int !seed)
+                               in
+                                C.Lambda (binder',source,(aux target (k+1)))
+                            | _ ->
+                               let nr_param_constr = k - 1 - paramsno in
+                                if id = i_constr_id
+                                 then C.Rel (k - i)
+                                 else S.lift (nr_param_constr + 1) t1' (* + 1 per liftare anche il lambda aggiunto esternamente al case *)
+                          in aux reduced_cty 1
+                       ) constructor_list in
+                     let outtype =
+                      let seed = ref 0 in
+                      let rec to_lambdas te head =
+                       match CicReduction.whd context te with
+                        | C.Prod (binder,so,ta) ->
+                           let binder' =
+                            match binder with
+                               C.Name _ -> binder
+                             | C.Anonymous ->
+                                C.Name (incr seed; "d" ^ string_of_int !seed)
+                           in
+                            C.Lambda (binder',so,to_lambdas ta head)
+                        | _ -> head in
+                      let rec skip_prods n te =
+                       match n, CicReduction.whd context te with
+                          0, _ -> te
+                        | n, C.Prod (_,_,ta) -> skip_prods (n - 1) ta
+                        | _, _ -> assert false
+                      in
+                       let abstracted_tty =
+                        match CicSubstitution.lift (paramsno + 1) tty with
+                           C.MutInd _ as tty' -> tty'
+                         | C.Appl l ->
+                             let keep,abstract =
+                              HExtlib.split_nth (paramsno +1) l in
+                             let rec mk_rels =
+                              function
+                                 0 -> []
+                               | n -> C.Rel n :: (mk_rels (n - 1))
+                             in
+                              C.Appl (keep@mk_rels (List.length abstract))
+                         | _ -> assert false
+                       in
+                        match ind_type_list with
+                           [] -> assert false
+                         | (_,_,ty,_)::_ ->
+                            to_lambdas (skip_prods paramsno ty)
+                             (C.Lambda (C.Name "x", abstracted_tty,
+                               S.lift (2+paramsno) tty'))
+                      in
+                       patterns,outtype
+                  | _ -> raise (ProofEngineTypes.Fail (lazy "Discriminate: object is not an Inductive Definition: it's imposible"))
                 in
                 ProofEngineTypes.apply_tactic   
                  (T.thens 
-                  ~start:(P.cut_tac (C.Appl [(C.MutInd (equri,0,[])) ; tty' ; t1' ; t2']))
-                  ~continuations:[
-                    T.then_ 
-                     ~start:(injection_tac ~term:(C.Rel 1))
-                     ~continuation:T.id_tac (* !!! qui devo anche fare clear di term tranne al primo passaggio *) 
-                    ;
-                    T.then_ 
-                     ~start:(ProofEngineTypes.mk_tactic 
-                       (fun status ->    
-                         let (proof, goal) = status in
-                         let _,metasenv,_,_ = proof in
-                          let _,context,gty = CicUtil.lookup_meta goal metasenv in
-                           let new_t1' = 
-                            match gty with 
-                               (C.Appl (C.MutInd (_,_,_)::arglist)) -> 
-                                List.nth arglist 1
-                             | _ -> raise (ProofEngineTypes.Fail (lazy "Injection: goal after cut is not correct"))
-                           in
-                            ProofEngineTypes.apply_tactic 
-                            (ReductionTactics.change_tac
-                               ~pattern:(ProofEngineTypes.conclusion_pattern
-                                (Some new_t1'))
-                               (fun _ m u ->
-                                 C.Appl [ C.Lambda (C.Name "x", tty,
-                                  C.MutCase (turi, typeno,
-                                   (C.Lambda ((C.Name "x"),
-                                    (S.lift 1 tty),
-                                    (S.lift 2 tty'))),
-                                   (C.Rel 1), pattern
-                                  )
-                                 );
-                                 t1], m, u))
-                        status
-                       ))
-                     ~continuation:
-                       (T.then_
-                         ~start:
-                           (EqualityTactics.rewrite_simpl_tac
-                             ~direction:`LeftToRight
-                             ~pattern:(ProofEngineTypes.conclusion_pattern None)
-                             term)
-                         ~continuation:EqualityTactics.reflexivity_tac
-                       )
+                  ~start:
+                    (P.cut_tac
+                     (C.Appl [C.MutInd (equri,0,[]) ; tty' ; t1' ; t2']))
+                  ~continuations:
+                    [ injection_tac ~first_time:false ~liftno:0
+                       ~term:(C.Rel 1)
+                       (* here I need to lift all the continuations by 1;
+                          since I am setting back liftno to 0, I actually
+                          need to lift all the continuations by liftno + 1 *)
+                       ~continuation:
+                         (fun ~liftno:x ->
+                           continuation ~liftno:(liftno + 1 + x)) ;
+                      T.then_ 
+                       ~start:(ProofEngineTypes.mk_tactic 
+                         (fun status ->    
+                           let (proof, goal) = status in
+                           let _,metasenv,_,_ = proof in
+                            let _,context,gty =
+                             CicUtil.lookup_meta goal metasenv
+                            in
+                             let new_t1' = 
+                              match gty with 
+                                 (C.Appl (C.MutInd (_,_,_)::arglist)) -> 
+                                  List.nth arglist 1
+                               | _ ->
+                                 raise
+                                  (ProofEngineTypes.Fail
+                                    (lazy
+                                      "Injection: goal after cut is not correct"))
+                             in
+                              ProofEngineTypes.apply_tactic 
+                              (ReductionTactics.change_tac
+                                 ~pattern:(ProofEngineTypes.conclusion_pattern
+                                  (Some new_t1'))
+                                 (fun _ m u ->
+                                   C.Appl [
+                                    C.Lambda
+                                     (C.Name "x",
+                                       tty,
+                                       C.MutCase
+                                        (turi,typeno,outtype,C.Rel 1,patterns)) ;
+                                    t1],
+                                   m, u))
+                          status
+                         ))
+                       ~continuation:
+                         (T.then_
+                           ~start:
+                             (EqualityTactics.rewrite_simpl_tac
+                               ~direction:`LeftToRight
+                               ~pattern:(ProofEngineTypes.conclusion_pattern None)
+                               term)
+                           ~continuation:EqualityTactics.reflexivity_tac)
                    ])     
                   status
-            | _ -> raise (ProofEngineTypes.Fail (lazy "Discriminate: not a discriminable equality"))
+            | _ -> raise (ProofEngineTypes.Fail (lazy "Injection: not an equality over elements of an inductive type"))
            )
-        | _ -> raise (ProofEngineTypes.Fail (lazy "Discriminate: not an equality"))
+        | _ -> raise (ProofEngineTypes.Fail (lazy "Injection: not an equality"))
  in
   ProofEngineTypes.mk_tactic (injection1_tac ~term ~i)
 ;;
 
+let injection_tac =
+ injection_tac ~first_time:true ~liftno:0 ~continuation:(fun ~liftno -> Tacticals.id_tac)
+;;
+
 exception TwoDifferentSubtermsFound of int 
 
 (* term ha tipo t1=t2; funziona solo se t1 e t2 hanno in testa costruttori