From 0bf30da6d3f539145bac0213887789f87bc8cc6a Mon Sep 17 00:00:00 2001
From: Claudio Sacerdoti Coen <claudio.sacerdoticoen@unibo.it>
Date: Sat, 2 Jul 2005 13:59:16 +0000
Subject: [PATCH] New theorem: eq_ind_r.

---
 helm/matita/library/equality.ma | 7 +++++++
 1 file changed, 7 insertions(+)

diff --git a/helm/matita/library/equality.ma b/helm/matita/library/equality.ma
index c49475c13..cf513734a 100644
--- a/helm/matita/library/equality.ma
+++ b/helm/matita/library/equality.ma
@@ -26,6 +26,13 @@ theorem trans_eq : \forall A:Type.
 intros.elim H1.assumption.
 qed.
 
+theorem eq_ind_r :
+ \forall A:Type.\forall x:A. \forall P: A \to Prop.
+   P x \to \forall y:A. eq A y x \to P y.
+intros.letin H1' \def sym_eq ? ? ? H1.clearbody H1'.
+elim H1'.assumption.
+qed.
+
 theorem f_equal: \forall  A,B:Type.\forall f:A\to B.
 \forall x,y:A. eq A x y \to eq B (f x) (f y).
 intros.elim H.apply refl_equal.
-- 
2.39.2