X-Git-Url: http://matita.cs.unibo.it/gitweb/?a=blobdiff_plain;f=helm%2Fsoftware%2Fmatita%2Flibrary%2Flogic%2Fcoimplication.ma;h=a963846f093a1cc362447baa2e85011539f5998d;hb=59d7f64e2e1a22ded8f9017942ca640fe62d886a;hp=9edb4949c532c23ee43679ae11ad2ecac123d4bf;hpb=5e01cba364607e7937aec2e359c34f049bb0f108;p=helm.git

diff --git a/helm/software/matita/library/logic/coimplication.ma b/helm/software/matita/library/logic/coimplication.ma
index 9edb4949c..a963846f0 100644
--- a/helm/software/matita/library/logic/coimplication.ma
+++ b/helm/software/matita/library/logic/coimplication.ma
@@ -31,17 +31,17 @@ notation < "hvbox(a break \leftrightarrow b)"
 for @{ 'iff $a $b }.
 
 theorem iff_intro: \forall A,B. (A \to B) \to (B \to A) \to (A \liff B).
- unfold Iff. intros. split; intros; auto.
+ unfold Iff. intros. split; intros; autobatch.
 qed.
 
 theorem iff_refl: \forall A. A \liff A.
- intros. apply iff_intro; intros; auto.
+ intros. apply iff_intro; intros; autobatch.
 qed.
 
 theorem iff_sym: \forall A,B. A \liff B \to B \liff A.
- intros. decompose. apply iff_intro; intros; auto.
+ intros. elim H. apply iff_intro[assumption|assumption]
 qed.
 
 theorem iff_trans: \forall A,B,C. A \liff B \to B \liff C \to A \liff C.
- intros. decompose. apply iff_intro; intros; auto.
+ intros. elim H. elim H1. apply iff_intro;intros;autobatch.
 qed.