X-Git-Url: http://matita.cs.unibo.it/gitweb/?a=blobdiff_plain;f=helm%2FgTopLevel%2FproofEngineReduction.ml;h=bb724fc758d2736c40a7c199b60898501fe4308a;hb=a4df9661e15509e5da6ed9c57e3ab6a27a440c3f;hp=265e5f99ceb37049618a27e6c86e07c363ea60fd;hpb=d7a329578a475af98aa5f2a16d9873a576dab599;p=helm.git

diff --git a/helm/gTopLevel/proofEngineReduction.ml b/helm/gTopLevel/proofEngineReduction.ml
index 265e5f99c..bb724fc75 100644
--- a/helm/gTopLevel/proofEngineReduction.ml
+++ b/helm/gTopLevel/proofEngineReduction.ml
@@ -47,59 +47,65 @@ exception RelToHiddenHypothesis;;
 
 (* syntactic_equality up to cookingsno for uris *)
 (* (which is often syntactically irrilevant)    *)
-let rec syntactic_equality t t' =
+let syntactic_equality ~alpha_equivalence =
  let module C = Cic in
-  if t = t' then true
-  else
-   match t,t' with
-      C.Rel _, C.Rel _
-    | C.Var _, C.Var _
-    | C.Meta _, C.Meta _
-    | C.Sort _, C.Sort _
-    | C.Implicit, C.Implicit -> false (* we already know that t != t' *)
-    | C.Cast (te,ty), C.Cast (te',ty') ->
-       syntactic_equality te te' &&
-        syntactic_equality ty ty'
-    | C.Prod (n,s,t), C.Prod (n',s',t') ->
-       n = n' &&
-        syntactic_equality s s' &&
-         syntactic_equality t t'
-    | C.Lambda (n,s,t), C.Lambda (n',s',t') ->
-       n = n' &&
-        syntactic_equality s s' &&
-         syntactic_equality t t'
-    | C.LetIn (n,s,t), C.LetIn(n',s',t') ->
-       n = n' &&
-        syntactic_equality s s' &&
-         syntactic_equality t t'
-    | C.Appl l, C.Appl l' ->
-       List.fold_left2 (fun b t1 t2 -> b && syntactic_equality t1 t2) true l l'
-    | C.Const (uri,_), C.Const (uri',_) -> UriManager.eq uri uri'
-    | C.MutInd (uri,_,i), C.MutInd (uri',_,i') ->
-       UriManager.eq uri uri' && i = i'
-    | C.MutConstruct (uri,_,i,j), C.MutConstruct (uri',_,i',j') ->
-       UriManager.eq uri uri' && i = i' && j = j'
-    | C.MutCase (sp,_,i,outt,t,pl), C.MutCase (sp',_,i',outt',t',pl') ->
-       UriManager.eq sp sp' && i = i' &&
-        syntactic_equality outt outt' &&
-         syntactic_equality t t' &&
+  let rec aux t t' =
+   if t = t' then true
+   else
+    match t,t' with
+       C.Rel _, C.Rel _
+     | C.Var _, C.Var _
+     | C.Meta _, C.Meta _
+     | C.Sort _, C.Sort _
+     | C.Implicit, C.Implicit -> false (* we already know that t != t' *)
+     | C.Cast (te,ty), C.Cast (te',ty') ->
+        aux te te' && aux ty ty'
+     | C.Prod (n,s,t), C.Prod (n',s',t') ->
+        (alpha_equivalence || n = n') && aux s s' && aux t t'
+     | C.Lambda (n,s,t), C.Lambda (n',s',t') ->
+        (alpha_equivalence || n = n') && aux s s' && aux t t'
+     | C.LetIn (n,s,t), C.LetIn(n',s',t') ->
+        (alpha_equivalence || n = n') && aux s s' && aux t t'
+     | C.Appl l, C.Appl l' ->
+        (try
           List.fold_left2
-           (fun b t1 t2 -> b && syntactic_equality t1 t2) true pl pl'
-    | C.Fix (i,fl), C.Fix (i',fl') ->
-       i = i' &&
-        List.fold_left2
-         (fun b (name,i,ty,bo) (name',i',ty',bo') ->
-           b && name = name' && i = i' &&
-            syntactic_equality ty ty' &&
-             syntactic_equality bo bo') true fl fl'
-    | C.CoFix (i,fl), C.CoFix (i',fl') ->
-       i = i' &&
-        List.fold_left2
-         (fun b (name,ty,bo) (name',ty',bo') ->
-           b && name = name' &&
-            syntactic_equality ty ty' &&
-             syntactic_equality bo bo') true fl fl'
-    | _,_ -> false
+           (fun b t1 t2 -> b && aux t1 t2) true l l'
+         with
+          Invalid_argument _ -> false)
+     | C.Const (uri,_), C.Const (uri',_) -> UriManager.eq uri uri'
+     | C.MutInd (uri,_,i), C.MutInd (uri',_,i') ->
+        UriManager.eq uri uri' && i = i'
+     | C.MutConstruct (uri,_,i,j), C.MutConstruct (uri',_,i',j') ->
+        UriManager.eq uri uri' && i = i' && j = j'
+     | C.MutCase (sp,_,i,outt,t,pl), C.MutCase (sp',_,i',outt',t',pl') ->
+        UriManager.eq sp sp' && i = i' &&
+         aux outt outt' && aux t t' &&
+          (try
+            List.fold_left2
+             (fun b t1 t2 -> b && aux t1 t2) true pl pl'
+           with
+            Invalid_argument _ -> false)
+     | C.Fix (i,fl), C.Fix (i',fl') ->
+        i = i' &&
+        (try
+          List.fold_left2
+           (fun b (name,i,ty,bo) (name',i',ty',bo') ->
+             b && (alpha_equivalence || name = name') && i = i' &&
+              aux ty ty' && aux bo bo') true fl fl'
+         with
+          Invalid_argument _ -> false)
+     | C.CoFix (i,fl), C.CoFix (i',fl') ->
+        i = i' &&
+        (try
+          List.fold_left2
+           (fun b (name,ty,bo) (name',ty',bo') ->
+             b && (alpha_equivalence || name = name') &&
+              aux ty ty' && aux bo bo') true fl fl'
+         with
+          Invalid_argument _ -> false)
+     | _,_ -> false
+ in
+  aux
 ;;
 
 (* "textual" replacement of a subterm with another one *)
@@ -149,32 +155,36 @@ let replace ~equality ~what ~with_what ~where =
 (* replaces in a term a term with another one. *)
 (* Lifting are performed as usual.             *)
 let replace_lifting ~equality ~what ~with_what ~where =
- let rec substaux k =
+ let rec substaux k what =
   let module C = Cic in
+  let module S = CicSubstitution in
    function
-      t when (equality t what) -> CicSubstitution.lift (k-1) with_what
-    | C.Rel n as t -> t (*CSC: ??? BUG ? *)
+      t when (equality t what) -> S.lift (k-1) with_what
+    | C.Rel n as t -> t
     | C.Var _ as t  -> t
     | C.Meta (i, l) as t -> 
        let l' =
         List.map
          (function
              None -> None
-           | Some t -> Some (substaux k t)
+           | Some t -> Some (substaux k what t)
          ) l
        in
         C.Meta(i,l')
     | C.Sort _ as t -> t
     | C.Implicit as t -> t
-    | C.Cast (te,ty) -> C.Cast (substaux k te, substaux k ty)
-    | C.Prod (n,s,t) -> C.Prod (n, substaux k s, substaux (k + 1) t)
-    | C.Lambda (n,s,t) -> C.Lambda (n, substaux k s, substaux (k + 1) t)
-    | C.LetIn (n,s,t) -> C.LetIn (n, substaux k s, substaux (k + 1) t)
+    | C.Cast (te,ty) -> C.Cast (substaux k what te, substaux k what ty)
+    | C.Prod (n,s,t) ->
+       C.Prod (n, substaux k what s, substaux (k + 1) (S.lift 1 what) t)
+    | C.Lambda (n,s,t) ->
+       C.Lambda (n, substaux k what s, substaux (k + 1) (S.lift 1 what) t)
+    | C.LetIn (n,s,t) ->
+       C.LetIn (n, substaux k what s, substaux (k + 1) (S.lift 1 what) t)
     | C.Appl (he::tl) ->
        (* Invariant: no Appl applied to another Appl *)
-       let tl' = List.map (substaux k) tl in
+       let tl' = List.map (substaux k what) tl in
         begin
-         match substaux k he with
+         match substaux k what he with
             C.Appl l -> C.Appl (l@tl')
           | _ as he' -> C.Appl (he'::tl')
         end
@@ -183,13 +193,14 @@ let replace_lifting ~equality ~what ~with_what ~where =
     | C.MutInd _ as t -> t
     | C.MutConstruct _ as t -> t
     | C.MutCase (sp,cookingsno,i,outt,t,pl) ->
-       C.MutCase (sp,cookingsno,i,substaux k outt, substaux k t,
-        List.map (substaux k) pl)
+       C.MutCase (sp,cookingsno,i,substaux k what outt, substaux k what t,
+        List.map (substaux k what) pl)
     | C.Fix (i,fl) ->
        let len = List.length fl in
        let substitutedfl =
         List.map
-         (fun (name,i,ty,bo) -> (name, i, substaux k ty, substaux (k+len) bo))
+         (fun (name,i,ty,bo) ->
+           (name, i, substaux k what ty, substaux (k+len) (S.lift len what) bo))
           fl
        in
         C.Fix (i, substitutedfl)
@@ -197,12 +208,13 @@ let replace_lifting ~equality ~what ~with_what ~where =
        let len = List.length fl in
        let substitutedfl =
         List.map
-         (fun (name,ty,bo) -> (name, substaux k ty, substaux (k+len) bo))
+         (fun (name,ty,bo) ->
+           (name, substaux k what ty, substaux (k+len) (S.lift len what) bo))
           fl
        in
         C.CoFix (i, substitutedfl)
  in
-  substaux 1 where
+  substaux 1 what where
 ;;
 
 (* Takes a well-typed term and fully reduces it. *)