src/HOL/Divides.thy
changeset 8961 b547482dd127
parent 8902 a705822f4e2a
child 10212 33fe2d701ddd
--- a/src/HOL/Divides.thy	Wed May 24 18:48:03 2000 +0200
+++ b/src/HOL/Divides.thy	Wed May 24 18:48:22 2000 +0200
@@ -13,8 +13,8 @@
 axclass
   div < term
 
-instance
-  nat :: div
+instance  nat :: div
+instance  nat :: plus_ac0 (add_commute,add_assoc,add_0)
 
 consts
   div  :: ['a::div, 'a]  => 'a          (infixl 70)