src/HOL/Library/Fraction_Field.thy
changeset 36348 89c54f51f55a
parent 36331 6b9e487450ba
child 36409 d323e7773aa8
--- a/src/HOL/Library/Fraction_Field.thy	Mon Apr 26 11:34:15 2010 +0200
+++ b/src/HOL/Library/Fraction_Field.thy	Mon Apr 26 11:34:15 2010 +0200
@@ -267,7 +267,7 @@
 
 end
 
-instance fract :: (idom) division_by_zero
+instance fract :: (idom) division_ring_inverse_zero
 proof
   show "inverse 0 = (0:: 'a fract)" by (simp add: fract_expand)
     (simp add: fract_collapse)
@@ -450,7 +450,7 @@
         by simp
       with F have "(a * d) * (b * d) * ?F * ?F \<le> (c * b) * (b * d) * ?F * ?F"
         by (simp add: mult_le_cancel_right)
-      with neq show ?thesis by (simp add: ring_simps)
+      with neq show ?thesis by (simp add: field_simps)
     qed
   qed
   show "q < r ==> 0 < s ==> s * q < s * r"