--- /dev/null Thu Jan 01 00:00:00 1970 +0000
+++ b/src/HOL/Subst/UTLemmas.thy Tue Mar 21 13:22:28 1995 +0100
@@ -0,0 +1,20 @@
+(* Title: Substitutions/utermlemmas.thy
+ Author: Martin Coen, Cambridge University Computer Laboratory
+ Copyright 1993 University of Cambridge
+
+Additional definitions for uterms that are not part of the basic inductive definition.
+*)
+
+UTLemmas = UTerm + Setplus +
+
+consts
+
+ vars_of :: "'a uterm=>'a set"
+ "<:" :: "['a uterm,'a uterm]=>bool" (infixl 54)
+
+rules (*Definitions*)
+
+ vars_of_def "vars_of(t) == uterm_rec t (%x.{x}) (%x.{}) (%u v q r.q Un r)"
+ occs_def "s <: t == uterm_rec t (%x.False) (%x.False) (%u v q r.s=u | s=v | q | r)"
+
+end