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| author |  letouzey <letouzey@85f007b7-540e-0410-9357-904b9bb8a0f7> | 2011-05-05 15:13:04 +0000 |
|---|---|---|
| committer | letouzey <letouzey@85f007b7-540e-0410-9357-904b9bb8a0f7> | 2011-05-05 15:13:04 +0000 |
| commit | 959543f6f899f0384394f9770abbf17649f69b81 (patch) | |
| tree | 46dc4791f1799a3b2095bec6d887d9aa54f42ad3 /theories/ZArith/Zeven.v | |
| parent | d2bd5d87d23d443f6e41496bdfe5f8e82d675634 (diff) | |
BinInt: Z.add become the alternative Z.add'
It relies on Z.pos_sub instead of a Pos.compare followed by Pos.sub.
Proofs seem to be quite easy to adapt, via some rewrite Z.pos_sub_spec.
git-svn-id: svn+ssh://scm.gforge.inria.fr/svn/coq/trunk@14107 85f007b7-540e-0410-9357-904b9bb8a0f7
Diffstat (limited to 'theories/ZArith/Zeven.v')
| -rw-r--r-- | theories/ZArith/Zeven.v | 2 |
1 files changed, 1 insertions, 1 deletions
diff --git a/theories/ZArith/Zeven.v b/theories/ZArith/Zeven.v index ef91f2d77..d37a6a9c3 100644 --- a/theories/ZArith/Zeven.v +++ b/theories/ZArith/Zeven.v @@ -169,7 +169,7 @@ Lemma Zdiv2_odd_eqn : forall n, n = 2*(Zdiv2 n) + if Zodd_bool n then 1 else 0. Proof. intros [ |[p|p| ]|[p|p| ]]; simpl; trivial. - f_equal. now rewrite xO_succ_permute, <-Ppred_minus, Ppred_succ. + f_equal. symmetry. apply Pos.pred_double_succ. Qed. Lemma Zeven_div2 : forall n:Z, Zeven n -> n = 2 * Zdiv2 n. |