# HG changeset patch
# User nipkow
# Date 1596464493 -7200
# Node ID 2030eacf3a723dda2d94b6da8e43fcf4bda1ff7d
# Parent  8c355e2dd7dbf80697c2b5be7e8e62786657d86f
added lemma

diff -r 8c355e2dd7db -r 2030eacf3a72 src/HOL/Data_Structures/Tree2.thy
--- a/src/HOL/Data_Structures/Tree2.thy	Sat Aug 01 17:43:30 2020 +0000
+++ b/src/HOL/Data_Structures/Tree2.thy	Mon Aug 03 16:21:33 2020 +0200
@@ -36,4 +36,7 @@
 lemma set_inorder[simp]: "set (inorder t) = set_tree t"
 by (induction t) auto
 
+lemma length_inorder[simp]: "length (inorder t) = size t"
+by (induction t) auto
+
 end