src/HOL/Library/Cardinality.thy
changeset 48058 11a732f7d79f
parent 48053 9bc78a08ff0a
child 48059 f6ce99d3719b
--- a/src/HOL/Library/Cardinality.thy	Fri Jun 01 08:32:26 2012 +0200
+++ b/src/HOL/Library/Cardinality.thy	Fri Jun 01 13:52:51 2012 +0200
@@ -44,7 +44,7 @@
 lemma card_unit [simp]: "CARD(unit) = 1"
   unfolding UNIV_unit by simp
 
-lemma card_prod [simp]: "CARD('a \<times> 'b) = CARD('a::finite) * CARD('b::finite)"
+lemma card_prod [simp]: "CARD('a \<times> 'b) = CARD('a) * CARD('b)"
   unfolding UNIV_Times_UNIV [symmetric] by (simp only: card_cartesian_product)
 
 lemma card_sum [simp]: "CARD('a + 'b) = CARD('a::finite) + CARD('b::finite)"