diff options
| author |  filliatr <filliatr@85f007b7-540e-0410-9357-904b9bb8a0f7> | 2002-05-14 07:56:24 +0000 |
|---|---|---|
| committer | filliatr <filliatr@85f007b7-540e-0410-9357-904b9bb8a0f7> | 2002-05-14 07:56:24 +0000 |
| commit | f9fa6972e704267df4ff39b3eabbc04bec7f15c4 (patch) | |
| tree | 693fcda2effa1e2cdd6cb03d51775ef96cf166c1 /theories/ZArith/Zcomplements.v | |
| parent | 9f9175ae2ba591be2f2b626c5f21739df46e501f (diff) | |
nouveaux lemmes dans Zdiv (Claude Marche)
git-svn-id: svn+ssh://scm.gforge.inria.fr/svn/coq/trunk@2677 85f007b7-540e-0410-9357-904b9bb8a0f7
Diffstat (limited to 'theories/ZArith/Zcomplements.v')
| -rw-r--r-- | theories/ZArith/Zcomplements.v | 17 |
1 files changed, 17 insertions, 0 deletions
diff --git a/theories/ZArith/Zcomplements.v b/theories/ZArith/Zcomplements.v index 20309ab06..2ce09a752 100644 --- a/theories/ZArith/Zcomplements.v +++ b/theories/ZArith/Zcomplements.v @@ -249,3 +249,20 @@ Rewrite Zopp_Zopp;Intros. Elim (H `|m|`);Intros;Auto with zarith. Elim (Zabs_dec m);Intro eq;Rewrite eq;Trivial. Qed. + +(** To do case analysis over the sign of [z] *) + +Unset Implicit Arguments. + +Lemma Zcases : (x:Z)(P:Prop) + (`x=0`->P)-> + (`x>0`->P)-> + (`x<0`->P)->P. +Proof. +Intros x P Hzero Hpos Hneg. +Induction x. +Apply Hzero; Trivial. +Apply Hpos; Apply POS_gt_ZERO. +Apply Hneg; Apply NEG_lt_ZERO. +Save. + |