doc-src/TutorialI/Trie/Option2.thy
author wenzelm
Wed, 20 Sep 2000 00:50:09 +0200
changeset 10037 0d2a6feeb634
parent 8771 026f37a86ea7
permissions -rw-r--r--
updated;

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

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