X-Git-Url: http://matita.cs.unibo.it/gitweb/?a=blobdiff_plain;f=matita%2Fmatita%2Fcontribs%2Flambda_delta%2Fground_2%2Fxoa_props.ma;h=71216d1c4dee1cc0795580468c082e67dfb47473;hb=5613a25cee29ef32a597cb4b44e8f2f4d71c4df0;hp=e212a60e540ac30a058d3fe35fedb797312ebbd6;hpb=a8c166f1e1baeeae04553058bd179420ada8bbe7;p=helm.git

diff --git a/matita/matita/contribs/lambda_delta/ground_2/xoa_props.ma b/matita/matita/contribs/lambda_delta/ground_2/xoa_props.ma
index e212a60e5..71216d1c4 100644
--- a/matita/matita/contribs/lambda_delta/ground_2/xoa_props.ma
+++ b/matita/matita/contribs/lambda_delta/ground_2/xoa_props.ma
@@ -12,9 +12,14 @@
 (*                                                                        *)
 (**************************************************************************)
 
+include "basics/logic.ma".
 include "ground_2/xoa_notation.ma".
 include "ground_2/xoa.ma".
 
+interpretation "logical false" 'false = False.
+
+interpretation "logical true" 'true = True.
+
 lemma ex2_1_comm: ∀A0. ∀P0,P1:A0→Prop. (∃∃x0. P0 x0 & P1 x0) → ∃∃x0. P1 x0 & P0 x0.
 #A0 #P0 #P1 * /2 width=3/
 qed.