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authorGravatar Thomas Sibut-Pinote <thomas.sibut-pinote@inria.fr>2017-02-01 17:58:32 +0100
committerGravatar Thomas Sibut-Pinote <thomas.sibut-pinote@inria.fr>2017-02-15 17:56:14 +0100
commitf5c81ac1bcae7c40d5e89229647c06c97b5ddc85 (patch)
treea5a2769d37103cdf9aff3314cc451b340b86ca18 /theories/Reals/Rpower.v
parentc17c3faee20251cd5c7168246e9ffcd12d557f85 (diff)
Added some theory on powerRZ.
For this, I used a new inductive type Z_spec to reason on Z.
Diffstat (limited to 'theories/Reals/Rpower.v')
-rw-r--r--theories/Reals/Rpower.v14
1 files changed, 14 insertions, 0 deletions
diff --git a/theories/Reals/Rpower.v b/theories/Reals/Rpower.v
index b3ce6fa33..93462a1fc 100644
--- a/theories/Reals/Rpower.v
+++ b/theories/Reals/Rpower.v
@@ -490,6 +490,20 @@ Proof.
apply exp_Ropp.
Qed.
+Lemma powerRZ_Rpower x z : (0 < x)%R -> powerRZ x z = Rpower x (IZR z).
+Proof.
+ intros Hx.
+ assert (x <> 0)%R
+ by now intros Habs; rewrite Habs in Hx; apply (Rlt_irrefl 0).
+ destruct (intP z).
+ - now rewrite Rpower_O.
+ - rewrite <- pow_powerRZ, <- Rpower_pow by assumption.
+ now rewrite INR_IZR_INZ.
+ - rewrite opp_IZR, Rpower_Ropp.
+ rewrite powerRZ_neg, powerRZ_inv by assumption.
+ now rewrite <- pow_powerRZ, <- INR_IZR_INZ, Rpower_pow.
+Qed.
+
Theorem Rle_Rpower :
forall e n m:R, 1 < e -> 0 <= n -> n <= m -> e ^R n <= e ^R m.
Proof.