diff -r dd58f13a8eb4 -r eb85850d3eb7 src/HOL/Complex/ex/Sqrt.thy
--- a/src/HOL/Complex/ex/Sqrt.thy	Fri Nov 17 02:19:55 2006 +0100
+++ b/src/HOL/Complex/ex/Sqrt.thy	Fri Nov 17 02:20:03 2006 +0100
@@ -18,7 +18,7 @@
 *}
 
 definition
-  rationals  ("\<rat>")
+  rationals  ("\<rat>") where
   "\<rat> = {x. \<exists>m n. n \<noteq> 0 \<and> \<bar>x\<bar> = real (m::nat) / real (n::nat)}"
 
 theorem rationals_rep [elim?]: