more canonical import

--- a/src/HOL/ex/Eval_Examples.thy	Tue Jul 14 15:55:27 2009 +0200
+++ b/src/HOL/ex/Eval_Examples.thy	Tue Jul 14 16:27:30 2009 +0200
@@ -3,7 +3,7 @@
 header {* Small examples for evaluation mechanisms *}
 
 theory Eval_Examples
-imports Code_Eval Rational
+imports Complex_Main
 begin
 
 text {* evaluation oracle *}