# HG changeset patch # User wenzelm # Date 979947286 -3600 # Node ID c03f7dcee8b25d6c75df04b5f3236fc8bf3939ad # Parent 58ddb5049335b44101444a54eceae11250a61cfb instance int :: ordered_ring moved to Ring_and_Field_Example, because it changes the way that int expressions get simplified, violating the strict library principle (cf. README.html); diff -r 58ddb5049335 -r c03f7dcee8b2 src/HOL/Library/Ring_and_Field.thy --- a/src/HOL/Library/Ring_and_Field.thy Sat Jan 20 00:32:56 2001 +0100 +++ b/src/HOL/Library/Ring_and_Field.thy Sat Jan 20 00:34:46 2001 +0100 @@ -139,26 +139,4 @@ theorems ring_distrib = right_distrib left_distrib - - -subsection {* Example: The ordered ring of integers *} - -instance int :: ordered_ring -proof - fix i j k :: int - show "(i + j) + k = i + (j + k)" by simp - show "i + j = j + i" by simp - show "0 + i = i" by simp - show "- i + i = 0" by simp - show "i - j = i + (-j)" by simp - show "(i * j) * k = i * (j * k)" by simp - show "i * j = j * i" by simp - show "#1 * i = i" by simp - show "0 = (#0::int)" by simp - show "(i + j) * k = i * k + j * k" by (simp add: int_distrib) - show "i \ j ==> k + i \ k + j" by simp - show "i < j ==> 0 < k ==> k * i < k * j" by (simp add: zmult_zless_mono2) - show "\i\ = (if i < 0 then -i else i)" by (simp only: zabs_def) -qed - end