doc-src/TutorialI/Trie/Option2.thy
author wenzelm
Fri, 15 Sep 2000 20:18:08 +0200
changeset 9994 b06f6d2eef5f
parent 8771 026f37a86ea7
permissions -rw-r--r--
XSYMBOL_INSTALLFONTS is back;

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

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