diff -r 2a683fb686fd -r cbc2ac19d783 src/CCL/ex/Nat.thy
--- a/src/CCL/ex/Nat.thy	Tue Nov 11 11:47:53 2014 +0100
+++ b/src/CCL/ex/Nat.thy	Tue Nov 11 13:40:13 2014 +0100
@@ -6,7 +6,7 @@
 section {* Programs defined over the natural numbers *}
 
 theory Nat
-imports Wfd
+imports "../Wfd"
 begin
 
 definition not :: "i=>i"