X-Git-Url: http://matita.cs.unibo.it/gitweb/?a=blobdiff_plain;f=matita%2Fmatita%2Fcontribs%2Flambdadelta%2Fground%2Flib%2Fsubset_equivalence.ma;h=cddb51e89370ace7f4e6ce76ca712220e05d6a6d;hb=cc178d85bc4fec05b6a9dd176f338b3275beb3d9;hp=b3957eaf304a6079d1dd03c0ccdbbcd9738b40ce;hpb=5489d0b66ed7bff17b9dedb89708f57f1d542adc;p=helm.git

diff --git a/matita/matita/contribs/lambdadelta/ground/lib/subset_equivalence.ma b/matita/matita/contribs/lambdadelta/ground/lib/subset_equivalence.ma
index b3957eaf3..cddb51e89 100644
--- a/matita/matita/contribs/lambdadelta/ground/lib/subset_equivalence.ma
+++ b/matita/matita/contribs/lambdadelta/ground/lib/subset_equivalence.ma
@@ -17,7 +17,7 @@ include "ground/lib/subset_inclusion.ma".
 
 (* EQUIVALENCE FOR SUBSETS **************************************************)
 
-definition subset_eq (A): relation2 𝒫❨A❩ 𝒫❨A❩ ≝
+definition subset_eq (A): relation2 (𝒫❨A❩) (𝒫❨A❩) ≝
            λu1,u2. ∧∧ u1 ⊆ u2 & u2 ⊆ u1.
 
 interpretation