--- /dev/null Thu Jan 01 00:00:00 1970 +0000
+++ b/src/HOL/Induct/Tree.thy Fri Jul 16 14:03:03 1999 +0200
@@ -0,0 +1,27 @@
+(* Title: HOL/Induct/Tree.thy
+ ID: $Id$
+ Author: Stefan Berghofer, TU Muenchen
+ Copyright 1999 TU Muenchen
+
+Infinitely branching trees
+*)
+
+Tree = Main +
+
+datatype 'a tree = Atom 'a | Branch "nat => 'a tree"
+
+consts
+ map_tree :: "('a => 'b) => 'a tree => 'b tree"
+
+primrec
+ "map_tree f (Atom a) = Atom (f a)"
+ "map_tree f (Branch ts) = Branch (%x. map_tree f (ts x))"
+
+consts
+ exists_tree :: "('a => bool) => 'a tree => bool"
+
+primrec
+ "exists_tree P (Atom a) = P a"
+ "exists_tree P (Branch ts) = (? x. exists_tree P (ts x))"
+
+end