src/HOL/NatBin.thy
changeset 25965 05df64f786a4
parent 25919 8b1c0d434824
child 26086 3c243098b64a
--- a/src/HOL/NatBin.thy	Fri Jan 25 14:53:58 2008 +0100
+++ b/src/HOL/NatBin.thy	Fri Jan 25 14:54:41 2008 +0100
@@ -18,12 +18,16 @@
 begin
 
 definition
-  nat_number_of_def [code inline]: "number_of v = nat (number_of (v\<Colon>int))"
+  nat_number_of_def [code inline]: "number_of v = nat (number_of v)"
 
 instance ..
 
 end
 
+lemma [code post]:
+  "nat (number_of v) = number_of v"
+  unfolding nat_number_of_def ..
+
 abbreviation (xsymbols)
   square :: "'a::power => 'a"  ("(_\<twosuperior>)" [1000] 999) where
   "x\<twosuperior> == x^2"