# HG changeset patch # User huffman # Date 1329816657 -3600 # Node ID 69a273fcd53a493dd70ffc29e9c173243d15c5c1 # Parent fdb84c40e0744d63edf07ba27ee0fee9897494f8 avoid using constant Int.neg diff -r fdb84c40e074 -r 69a273fcd53a src/HOL/Algebra/Group.thy --- a/src/HOL/Algebra/Group.thy Tue Feb 21 09:17:53 2012 +0100 +++ b/src/HOL/Algebra/Group.thy Tue Feb 21 10:30:57 2012 +0100 @@ -41,7 +41,7 @@ begin definition "int_pow G a z = (let p = nat_rec \\<^bsub>G\<^esub> (%u b. b \\<^bsub>G\<^esub> a) - in if neg z then inv\<^bsub>G\<^esub> (p (nat (-z))) else p (nat z))" + in if z < 0 then inv\<^bsub>G\<^esub> (p (nat (-z))) else p (nat z))" end locale monoid = @@ -391,7 +391,7 @@ text {* Power *} lemma (in group) int_pow_def2: - "a (^) (z::int) = (if neg z then inv (a (^) (nat (-z))) else a (^) (nat z))" + "a (^) (z::int) = (if z < 0 then inv (a (^) (nat (-z))) else a (^) (nat z))" by (simp add: int_pow_def nat_pow_def Let_def) lemma (in group) int_pow_0 [simp]: