doc-src/TutorialI/Trie/Option2.thy

--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/doc-src/TutorialI/Trie/Option2.thy	Wed Apr 19 11:56:31 2000 +0200
@@ -0,0 +1,9 @@
+(*<*)
+theory Option2 = Main:;
+(*>*)
+
+datatype 'a option = None | Some 'a
+
+(*<*)
+end
+(*>*)