doc-src/TutorialI/Trie/Option2.thy
author wenzelm
Tue, 29 Aug 2000 00:54:22 +0200
changeset 9712 e33422a2eb9c
parent 8771 026f37a86ea7
permissions -rw-r--r--
updated cong stuff;

(*<*)
theory Option2 = Main:;
(*>*)

datatype 'a option = None | Some 'a;
(*<*)
end
(*>*)