doc-src/TutorialI/Trie/Option2.thy
author paulson
Tue, 20 Jun 2000 11:51:21 +0200
changeset 9090 7141b912b0bb
parent 8771 026f37a86ea7
permissions -rw-r--r--
changed a step for the improved rules for setsum

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

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