X-Git-Url: http://matita.cs.unibo.it/gitweb/?a=blobdiff_plain;f=helm%2Fmatita%2Flibrary%2Fhigher_order_defs%2Ffunctions.ma;h=321ae46b7502c1578975b24ccdc25c4351065788;hb=28ac70d3f475442cda4ef30e0e9c0e6d012b2527;hp=da90d421177817ff8561794d66250f97c6ce4fda;hpb=5a702cea95883f7095c16b450e065ccb1714fc5a;p=helm.git

diff --git a/helm/matita/library/higher_order_defs/functions.ma b/helm/matita/library/higher_order_defs/functions.ma
index da90d4211..321ae46b7 100644
--- a/helm/matita/library/higher_order_defs/functions.ma
+++ b/helm/matita/library/higher_order_defs/functions.ma
@@ -20,10 +20,9 @@ definition injective: \forall A,B:Type.\forall f:A \to B.Prop
 \def \lambda A,B.\lambda f.
   \forall x,y:A.f x = f y \to x=y.
 
-(* we have still to attach exists *)
 definition surjective: \forall A,B:Type.\forall f:A \to B.Prop
 \def \lambda A,B.\lambda f.
-  \forall z:B.ex A (\lambda x:A.z=f x).
+  \forall z:B. \exists x:A.z=f x.
 
 definition symmetric: \forall A:Type.\forall f:A \to A\to A.Prop
 \def \lambda A.\lambda f.\forall x,y.f x y = f y x.