# HG changeset patch # User huffman # Date 1273423141 25200 # Node ID ba2a7096dd2bf414b938f690e48287533378465e # Parent 9e444b09fbef74992d1a5a661d0913832eb2a0b3# Parent acb789f3936bf1849abb9f0ba6a1d80e2a6a5d88 merged diff -r acb789f3936b -r ba2a7096dd2b src/HOL/Fields.thy --- a/src/HOL/Fields.thy Sun May 09 15:28:44 2010 +0200 +++ b/src/HOL/Fields.thy Sun May 09 09:39:01 2010 -0700 @@ -397,6 +397,14 @@ "a < 0 \ b < 0 \ inverse a \ inverse b \ b \ a" by (blast intro: le_imp_inverse_le_neg dest: inverse_le_imp_le_neg) +lemma one_less_inverse: + "0 < a \ a < 1 \ 1 < inverse a" + using less_imp_inverse_less [of a 1, unfolded inverse_1] . + +lemma one_le_inverse: + "0 < a \ a \ 1 \ 1 \ inverse a" + using le_imp_inverse_le [of a 1, unfolded inverse_1] . + lemma pos_le_divide_eq [field_simps]: "0 < c ==> (a \ b/c) = (a*c \ b)" proof - assume less: "0