diff -r bc8aee017f8a -r d13ad9a479f9 src/HOL/Integ/IntDiv.thy
--- a/src/HOL/Integ/IntDiv.thy	Fri Jan 19 13:16:37 2007 +0100
+++ b/src/HOL/Integ/IntDiv.thy	Fri Jan 19 15:13:47 2007 +0100
@@ -1243,7 +1243,7 @@
   apply (simp add: mult_ac)
   done
 
-lemma zdvd1_eq: "(x::int) dvd 1 = ( \<bar>x\<bar> = 1)"
+lemma zdvd1_eq[simp]: "(x::int) dvd 1 = ( \<bar>x\<bar> = 1)"
 proof
   assume d: "x dvd 1" hence "int (nat \<bar>x\<bar>) dvd int (nat 1)" by (simp add: zdvd_abs1)
   hence "nat \<bar>x\<bar> dvd 1" by (simp add: zdvd_int)