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authorGravatar letouzey <letouzey@85f007b7-540e-0410-9357-904b9bb8a0f7>2010-02-09 17:44:37 +0000
committerGravatar letouzey <letouzey@85f007b7-540e-0410-9357-904b9bb8a0f7>2010-02-09 17:44:37 +0000
commit959b8555351fcf30bd747b47167dd0dca96d34c6 (patch)
treeaddfbecca5220e560e544d289fcf9c249aadeec8 /theories/ZArith/Zabs.v
parent911c50439abdedd0f75856d43ff12e9615ec9980 (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.v15
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 *)