diff -r 1fead823c7c6 -r 6e15de7dd871 doc-src/TutorialI/ToyList/ToyList2
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/doc-src/TutorialI/ToyList/ToyList2	Tue Aug 28 14:37:57 2012 +0200
@@ -0,0 +1,21 @@
+lemma app_Nil2 [simp]: "xs @ [] = xs"
+apply(induct_tac xs)
+apply(auto)
+done
+
+lemma app_assoc [simp]: "(xs @ ys) @ zs = xs @ (ys @ zs)"
+apply(induct_tac xs)
+apply(auto)
+done
+
+lemma rev_app [simp]: "rev(xs @ ys) = (rev ys) @ (rev xs)"
+apply(induct_tac xs)
+apply(auto)
+done
+
+theorem rev_rev [simp]: "rev(rev xs) = xs"
+apply(induct_tac xs)
+apply(auto)
+done
+
+end