doc-src/TutorialI/Trie/Option2.thy
author wenzelm
Wed, 02 Aug 2000 19:40:14 +0200
changeset 9502 50ec59aff389
parent 8771 026f37a86ea7
permissions -rw-r--r--
adapted deriv;

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

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