--- a/src/HOL/Library/Quotient.thy Mon Dec 10 11:24:08 2007 +0100
+++ b/src/HOL/Library/Quotient.thy Mon Dec 10 11:24:09 2007 +0100
@@ -6,7 +6,7 @@
header {* Quotient types *}
theory Quotient
-imports Main
+imports PreList Hilbert_Choice
begin
text {*