diff -r 89c54f51f55a -r 39be26d1bc28 src/HOL/Library/Bit.thy
--- a/src/HOL/Library/Bit.thy	Mon Apr 26 11:34:15 2010 +0200
+++ b/src/HOL/Library/Bit.thy	Mon Apr 26 11:34:17 2010 +0200
@@ -49,7 +49,7 @@
 
 subsection {* Type @{typ bit} forms a field *}
 
-instantiation bit :: "{field, division_by_zero}"
+instantiation bit :: "{field, division_ring_inverse_zero}"
 begin
 
 definition plus_bit_def: