# HG changeset patch # User huffman # Date 1159806610 -7200 # Node ID 68ed2e514ca052a3aac326727ee972609f76ec5b # Parent e3a503048f9bb204d9edc844625a35af7266fc62 add lemmas norm_not_less_zero, norm_le_zero_iff diff -r e3a503048f9b -r 68ed2e514ca0 src/HOL/Real/RealVector.thy --- a/src/HOL/Real/RealVector.thy Mon Oct 02 17:33:13 2006 +0200 +++ b/src/HOL/Real/RealVector.thy Mon Oct 02 18:30:10 2006 +0200 @@ -406,14 +406,18 @@ apply (rule abs_mult) done -lemma norm_zero [simp]: "norm (0::'a::real_normed_vector) = 0" +lemma norm_zero [simp]: "norm (0::'a::normed) = 0" by simp -lemma zero_less_norm_iff [simp]: - fixes x :: "'a::real_normed_vector" - shows "(0 < norm x) = (x \ 0)" +lemma zero_less_norm_iff [simp]: "(0 < norm x) = (x \ (0::'a::normed))" by (simp add: order_less_le) +lemma norm_not_less_zero [simp]: "\ norm (x::'a::normed) < 0" +by (simp add: linorder_not_less) + +lemma norm_le_zero_iff [simp]: "(norm x \ 0) = (x = (0::'a::normed))" +by (simp add: order_le_less) + lemma norm_minus_cancel [simp]: fixes x :: "'a::real_normed_vector" shows "norm (- x) = norm x"