From: Andrea Asperti <andrea.asperti@unibo.it>
Date: Mon, 11 May 2009 16:20:24 +0000 (+0000)
Subject: A few lemmas about inclusion.
X-Git-Tag: make_still_working~3997
X-Git-Url: http://matita.cs.unibo.it/gitweb/?a=commitdiff_plain;h=f261b8315d0b14781ae78740feb476327083d664;p=helm.git

A few lemmas about inclusion.
---

diff --git a/helm/software/matita/library/list/in.ma b/helm/software/matita/library/list/in.ma
index d6c165022..310c3f369 100644
--- a/helm/software/matita/library/list/in.ma
+++ b/helm/software/matita/library/list/in.ma
@@ -152,4 +152,16 @@ qed.
 
 lemma incl_A_A: ∀T,A.incl T A A.
 intros.unfold incl.intros.assumption.
+qed.
+
+lemma incl_append_l : ∀T,A,B.incl T A (A @ B).
+unfold incl; intros;autobatch.
+qed.
+
+lemma incl_append_r : ∀T,A,B.incl T B (A @ B).
+unfold incl; intros;autobatch.
+qed.
+
+lemma incl_cons : ∀T,A,B,x.incl T A B → incl T (x::A) (x::B).
+unfold incl; intros;elim (in_list_cons_case ? ? ? ? H1);autobatch.
 qed.
\ No newline at end of file