some minor fixes

[helm.git] / helm / software / matita / contribs / formal_topology / overlap / subsets.ma

diff --git a/helm/software/matita/contribs/formal_topology/overlap/subsets.ma b/helm/software/matita/contribs/formal_topology/overlap/subsets.ma
index e6d1872166143e9f891ee27e89305a8cc0d5c658..4152f48529a54ea91d8ef461b6dcfd8b45144169 100644 (file)
--- a/helm/software/matita/contribs/formal_topology/overlap/subsets.ma
+++ b/helm/software/matita/contribs/formal_topology/overlap/subsets.ma
@@ -129,7 +129,7 @@ interpretation "union" 'union U V = (fun21 ___ (union _) U V).
 (* qua non riesco a mettere set *)
 definition singleton: ∀A:setoid. unary_morphism1 A (Ω \sup A).
  intros; constructor 1;
-  [ apply (λa:A.{b | eq ? a b}); unfold setoid1_of_setoid; simplify;
+  [ apply (λa:A.{b | a =_0 b}); unfold setoid1_of_setoid; simplify;
     intros; simplify;
     split; intro;
     apply (.= e1);