diff -r 000000000000 -r a5a9c433f639 src/ZF/ex/bt_fn.thy
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/src/ZF/ex/bt_fn.thy	Thu Sep 16 12:20:38 1993 +0200
@@ -0,0 +1,24 @@
+(*  Title: 	ZF/ex/bt-fn.thy
+    ID:         $Id$
+    Author: 	Lawrence C Paulson, Cambridge University Computer Laboratory
+    Copyright   1992  University of Cambridge
+
+Binary trees
+*)
+
+BT_Fn = BT +
+consts
+    bt_rec    	:: "[i, i, [i,i,i,i,i]=>i] => i"
+    n_nodes	:: "i=>i"
+    n_leaves   	:: "i=>i"
+    bt_reflect 	:: "i=>i"
+
+rules
+  bt_rec_def
+    "bt_rec(t,c,h) == Vrec(t, %t g.bt_case(c, %x y z. h(x,y,z,g`y,g`z), t))"
+
+  n_nodes_def	"n_nodes(t) == bt_rec(t,  0,  %x y z r s. succ(r#+s))"
+  n_leaves_def	"n_leaves(t) == bt_rec(t,  succ(0),  %x y z r s. r#+s)"
+  bt_reflect_def "bt_reflect(t) == bt_rec(t,  Lf,  %x y z r s. Br(x,s,r))"
+
+end