diff -r f0eff6393a32 -r 5c59114ff0cb src/HOL/NthRoot.thy
--- a/src/HOL/NthRoot.thy	Mon Jun 02 15:10:18 2014 +0200
+++ b/src/HOL/NthRoot.thy	Mon Jun 02 16:19:37 2014 +0200
@@ -461,7 +461,7 @@
   unfolding sqrt_def by (rule continuous_real_root)
   
 lemma continuous_on_real_sqrt[continuous_intros]:
-  "continuous_on s f \<Longrightarrow> 0 < n \<Longrightarrow> continuous_on s (\<lambda>x. sqrt (f x))"
+  "continuous_on s f \<Longrightarrow> continuous_on s (\<lambda>x. sqrt (f x))"
   unfolding sqrt_def by (rule continuous_on_real_root)
 
 lemma DERIV_real_sqrt_generic: