--- /dev/null Thu Jan 01 00:00:00 1970 +0000
+++ b/src/HOL/ex/Acc.thy Wed Mar 22 12:42:34 1995 +0100
@@ -0,0 +1,26 @@
+(* Title: HOL/ex/Acc.thy
+ ID: $Id$
+ Author: Lawrence C Paulson, Cambridge University Computer Laboratory
+ Copyright 1994 University of Cambridge
+
+Inductive definition of acc(r)
+
+See Ch. Paulin-Mohring, Inductive Definitions in the System Coq.
+Research Report 92-49, LIP, ENS Lyon. Dec 1992.
+*)
+
+Acc = WF +
+
+consts
+ pred :: "['b, ('a * 'b)set] => 'a set" (*Set of predecessors*)
+ acc :: "('a * 'a)set => 'a set" (*Accessible part*)
+
+defs
+ pred_def "pred x r == {y. <y,x>:r}"
+
+inductive "acc(r)"
+ intrs
+ pred "pred a r: Pow(acc(r)) ==> a: acc(r)"
+ monos "[Pow_mono]"
+
+end