src/HOL/Proofs/Extraction/Util.thy

--- a/src/HOL/Proofs/Extraction/Util.thy	Tue Mar 10 16:12:35 2015 +0000
+++ b/src/HOL/Proofs/Extraction/Util.thy	Mon Mar 16 15:30:00 2015 +0000
@@ -5,7 +5,7 @@
 section {* Auxiliary lemmas used in program extraction examples *}
 
 theory Util
-imports Old_Datatype
+imports "~~/src/HOL/Library/Old_Datatype"
 begin
 
 text {*