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| author |  Jason Gross <jgross@mit.edu> | 2017-05-13 12:44:43 -0400 |
|---|---|---|
| committer | Jason Gross <jgross@mit.edu> | 2017-05-13 12:44:43 -0400 |
| commit | 401058d999a6eaa38ce31b2ee9356a65b63498d2 (patch) | |
| tree | 12d050078c95a25a8f00e982196bbe1e64989415 /src/Util/ZUtil/Sgn.v | |
| parent | a30bbfe60d619e13601985340b1b70b150aecc28 (diff) | |
Split off more ZUtil things
Diffstat (limited to 'src/Util/ZUtil/Sgn.v')
| -rw-r--r-- | src/Util/ZUtil/Sgn.v | 12 |
1 files changed, 12 insertions, 0 deletions
diff --git a/src/Util/ZUtil/Sgn.v b/src/Util/ZUtil/Sgn.v new file mode 100644 index 000000000..a3e6182bc --- /dev/null +++ b/src/Util/ZUtil/Sgn.v @@ -0,0 +1,12 @@ +Require Import Coq.ZArith.ZArith Coq.omega.Omega. +Require Import Crypto.Util.ZUtil.Hints.Core. +Local Open Scope Z_scope. + +Module Z. + Lemma div_abs_sgn_nonneg a b : 0 <= Z.sgn (Z.abs a / Z.abs b). + Proof. + generalize (Zdiv_sgn (Z.abs a) (Z.abs b)). + destruct a, b; simpl; omega. + Qed. + Hint Resolve div_abs_sgn_nonneg : zarith. +End Z. |