--- a/src/HOL/Power.thy Thu May 17 08:42:51 2007 +0200
+++ b/src/HOL/Power.thy Thu May 17 08:53:57 2007 +0200
@@ -147,18 +147,18 @@
done
lemma field_power_eq_0_iff [simp]:
- "(a^n = 0) = (a = (0::'a::{field,recpower}) & 0<n)"
+ "(a^n = 0) = (a = (0::'a::{division_ring,recpower}) & 0<n)"
apply (induct "n")
apply (auto simp add: power_Suc field_mult_eq_0_iff zero_neq_one[THEN not_sym])
done
-lemma field_power_not_zero: "a \<noteq> (0::'a::{field,recpower}) ==> a^n \<noteq> 0"
+lemma field_power_not_zero: "a \<noteq> (0::'a::{division_ring,recpower}) ==> a^n \<noteq> 0"
by force
lemma nonzero_power_inverse:
- "a \<noteq> 0 ==> inverse ((a::'a::{field,recpower}) ^ n) = (inverse a) ^ n"
+ "a \<noteq> 0 ==> inverse ((a::'a::{division_ring,recpower}) ^ n) = (inverse a) ^ n"
apply (induct "n")
-apply (auto simp add: power_Suc nonzero_inverse_mult_distrib mult_commute)
+apply (auto simp add: power_Suc nonzero_inverse_mult_distrib power_commutes)
done
text{*Perhaps these should be simprules.*}