X-Git-Url: http://matita.cs.unibo.it/gitweb/?a=blobdiff_plain;f=matita%2Fmatita%2Flib%2Fbasics%2Fsets.ma;h=8e40b666bfdee2eb318478d2899a3bece809619f;hb=bf816f05ddbe0ded4948dd33490619724dc4f7cf;hp=7c791da41b07eeb308c124706a1901bb565f1141;hpb=fe7d9f4665e92d9c6934988b2b215547ab7ecf3f;p=helm.git

diff --git a/matita/matita/lib/basics/sets.ma b/matita/matita/lib/basics/sets.ma
index 7c791da41..8e40b666b 100644
--- a/matita/matita/lib/basics/sets.ma
+++ b/matita/matita/lib/basics/sets.ma
@@ -10,6 +10,8 @@
       V_______________________________________________________________ *)
 
 include "basics/logic.ma".
+include "basics/core_notation/singl_1.ma".
+include "basics/core_notation/subseteq_2.ma".
 
 (**** a subset of A is just an object of type A→Prop ****)
 
@@ -38,6 +40,7 @@ interpretation "subset" 'subseteq a b = (subset ? a b).
 
 (* extensional equality *)
 definition eqP ≝ λA:Type[0].λP,Q:A → Prop.∀a:A.P a ↔ Q a.
+(* ≐ is typed as \doteq *)
 notation "A ≐ B" non associative with precedence 45 for @{'eqP $A $B}.
 interpretation "extensional equality" 'eqP a b = (eqP ? a b).
 
@@ -115,4 +118,4 @@ qed.
 (* substraction *)
 lemma substract_def:∀U.∀A,B:U→Prop. A-B ≐ A ∩ ¬B.
 #U #A #B #w normalize /2/
-qed.
\ No newline at end of file
+qed.