diff options
author | letouzey <letouzey@85f007b7-540e-0410-9357-904b9bb8a0f7> | 2010-02-09 17:44:37 +0000 |
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committer | letouzey <letouzey@85f007b7-540e-0410-9357-904b9bb8a0f7> | 2010-02-09 17:44:37 +0000 |
commit | 959b8555351fcf30bd747b47167dd0dca96d34c6 (patch) | |
tree | addfbecca5220e560e544d289fcf9c249aadeec8 /theories/ZArith/Zabs.v | |
parent | 911c50439abdedd0f75856d43ff12e9615ec9980 (diff) |
ZBinary (impl of Numbers via Z) reworked, comes earlier, subsumes ZOrderedType
git-svn-id: svn+ssh://scm.gforge.inria.fr/svn/coq/trunk@12714 85f007b7-540e-0410-9357-904b9bb8a0f7
Diffstat (limited to 'theories/ZArith/Zabs.v')
-rw-r--r-- | theories/ZArith/Zabs.v | 15 |
1 files changed, 3 insertions, 12 deletions
diff --git a/theories/ZArith/Zabs.v b/theories/ZArith/Zabs.v index 36eb41104..ba454c327 100644 --- a/theories/ZArith/Zabs.v +++ b/theories/ZArith/Zabs.v @@ -23,21 +23,12 @@ Open Local Scope Z_scope. (**********************************************************************) (** * Properties of absolute value *) -Lemma Zabs_eq : forall n:Z, 0 <= n -> Zabs n = n. -Proof. - intro x; destruct x; auto with arith. - compute in |- *; intros; absurd (Gt = Gt); trivial with arith. -Qed. - -Lemma Zabs_non_eq : forall n:Z, n <= 0 -> Zabs n = - n. -Proof. - intro x; destruct x; auto with arith. - compute in |- *; intros; absurd (Gt = Gt); trivial with arith. -Qed. +Notation Zabs_eq := Zabs_eq (only parsing). (* 0 <= n -> Zabs n = n *) +Notation Zabs_non_eq := Zabs_non_eq (only parsing). (* n <= 0 -> Zabs n = -n *) Theorem Zabs_Zopp : forall n:Z, Zabs (- n) = Zabs n. Proof. - intros z; case z; simpl in |- *; auto. + intros z; case z; simpl; auto. Qed. (** * Proving a property of the absolute value by cases *) |