X-Git-Url: http://matita.cs.unibo.it/gitweb/?a=blobdiff_plain;f=helm%2Fsoftware%2Fcomponents%2Fcic_unification%2FcicUnification.ml;h=6004e73fa98e71497447e5d72357683907ea88c0;hb=9795c5698b48a9ce63fcf681fa63cb8f69cd1724;hp=44712199e412b370170b8753c6aa0e488d6a12bf;hpb=acfce0988db6cce820044b174f4f485dc0a0c6ec;p=helm.git

diff --git a/helm/software/components/cic_unification/cicUnification.ml b/helm/software/components/cic_unification/cicUnification.ml
index 44712199e..6004e73fa 100644
--- a/helm/software/components/cic_unification/cicUnification.ml
+++ b/helm/software/components/cic_unification/cicUnification.ml
@@ -457,18 +457,19 @@ debug_print (lazy ("restringo Meta n." ^ (string_of_int n) ^ "on variable n." ^
           (sprintf
             "Can't unify %s with %s due to different constants"
             (CicMetaSubst.ppterm subst t1) 
-            (CicMetaSubst.ppterm subst t2)))) 
+            (CicMetaSubst.ppterm subst t2))))
    | C.MutInd (uri1,i1,exp_named_subst1),C.MutInd (uri2,i2,exp_named_subst2) ->
        if UriManager.eq uri1 uri2 && i1 = i2 then
          fo_unif_subst_exp_named_subst 
            test_equality_only 
            subst context metasenv exp_named_subst1 exp_named_subst2 ugraph
        else
-         raise (UnificationFailure (lazy "4"))
-           (* (sprintf
-              "Can't unify %s with %s due to different inductive principles"
-              (CicMetaSubst.ppterm subst t1) 
-              (CicMetaSubst.ppterm subst t2))) *)
+         raise (UnificationFailure
+           (lazy
+            (sprintf
+             "Can't unify %s with %s due to different inductive principles"
+             (CicMetaSubst.ppterm subst t1) 
+             (CicMetaSubst.ppterm subst t2))))
    | C.MutConstruct (uri1,i1,j1,exp_named_subst1),
        C.MutConstruct (uri2,i2,j2,exp_named_subst2) ->
        if UriManager.eq uri1 uri2 && i1 = i2 && j1 = j2 then
@@ -476,11 +477,12 @@ debug_print (lazy ("restringo Meta n." ^ (string_of_int n) ^ "on variable n." ^
            test_equality_only 
            subst context metasenv exp_named_subst1 exp_named_subst2 ugraph
        else
-         raise (UnificationFailure (lazy "5"))
-           (* (sprintf
+         raise (UnificationFailure
+          (lazy
+            (sprintf
               "Can't unify %s with %s due to different inductive constructors"
               (CicMetaSubst.ppterm subst t1) 
-              (CicMetaSubst.ppterm subst t2))) *)
+              (CicMetaSubst.ppterm subst t2))))
    | (C.Implicit _, _) | (_, C.Implicit _) ->  assert false
    | (C.Cast (te,ty), t2) -> fo_unif_subst test_equality_only 
                               subst context metasenv te t2 ugraph
@@ -578,13 +580,14 @@ debug_print (lazy ("restringo Meta n." ^ (string_of_int n) ^ "on variable n." ^
                 fo_unif_l 
                   test_equality_only subst metasenv (lr1, lr2)  ugraph
               with 
-              | UnificationFailure _
-              | Uncertain _ as exn -> 
+              | UnificationFailure s
+              | Uncertain s as exn -> 
                   (match l1, l2 with
                   | (((Cic.Const (uri1, ens1)) as c1) :: tl1), 
                      (((Cic.Const (uri2, ens2)) as c2) :: tl2) when
                     CoercGraph.is_a_coercion c1 && 
-                    CoercGraph.is_a_coercion c2 ->
+                    CoercGraph.is_a_coercion c2 &&
+                    not (UriManager.eq uri1 uri2) ->
                       let body1, attrs1, ugraph = 
                         match CicEnvironment.get_obj ugraph uri1 with
                         | Cic.Constant (_,Some bo, _, _, attrs),u  -> bo,attrs,u
@@ -596,9 +599,15 @@ debug_print (lazy ("restringo Meta n." ^ (string_of_int n) ^ "on variable n." ^
                         | _ -> assert false
                       in
                       let is_composite1 = 
-                        List.exists ((=) (`Class `Coercion)) attrs1 in
+                        List.exists 
+                         (function `Class (`Coercion _) -> true | _-> false) 
+                         attrs1 
+                      in
                       let is_composite2 = 
-                        List.exists ((=) (`Class `Coercion)) attrs2 in
+                        List.exists 
+                         (function `Class (`Coercion _) -> true | _-> false) 
+                         attrs2 
+                      in
                       (match is_composite1, is_composite2 with
                       | false, false -> raise exn
                       | true, false ->