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authorGravatar bertot <bertot@85f007b7-540e-0410-9357-904b9bb8a0f7>2012-06-05 12:17:32 +0000
committerGravatar bertot <bertot@85f007b7-540e-0410-9357-904b9bb8a0f7>2012-06-05 12:17:32 +0000
commit9dea6a7404a251dbf7c467b445aca2686de59d22 (patch)
tree765772817c26d94ed5af763cda7bc4ee763644b1 /theories/Reals/AltSeries.v
parent83b88cee6a66f999a4198200eade41ef49f038c6 (diff)
Modifications and rearrangements to remove the action that sin (PI/2) = 1
Beware that the definition of PI changes in the process git-svn-id: svn+ssh://scm.gforge.inria.fr/svn/coq/trunk@15425 85f007b7-540e-0410-9357-904b9bb8a0f7
Diffstat (limited to 'theories/Reals/AltSeries.v')
-rw-r--r--theories/Reals/AltSeries.v12
1 files changed, 6 insertions, 6 deletions
diff --git a/theories/Reals/AltSeries.v b/theories/Reals/AltSeries.v
index 07a26929e..648055d93 100644
--- a/theories/Reals/AltSeries.v
+++ b/theories/Reals/AltSeries.v
@@ -414,27 +414,27 @@ Proof.
Qed.
(** Now, PI is defined *)
-Definition PI : R := 4 * (let (a,_) := exist_PI in a).
+Definition Alt_PI : R := 4 * (let (a,_) := exist_PI in a).
(** We can get an approximation of PI with the following inequality *)
-Lemma PI_ineq :
+Lemma Alt_PI_ineq :
forall N:nat,
- sum_f_R0 (tg_alt PI_tg) (S (2 * N)) <= PI / 4 <=
+ sum_f_R0 (tg_alt PI_tg) (S (2 * N)) <= Alt_PI / 4 <=
sum_f_R0 (tg_alt PI_tg) (2 * N).
Proof.
intro; apply alternated_series_ineq.
apply PI_tg_decreasing.
apply PI_tg_cv.
- unfold PI in |- *; case exist_PI; intro.
+ unfold Alt_PI in |- *; case exist_PI; intro.
replace (4 * x / 4) with x.
trivial.
unfold Rdiv in |- *; rewrite (Rmult_comm 4); rewrite Rmult_assoc;
rewrite <- Rinv_r_sym; [ rewrite Rmult_1_r; reflexivity | discrR ].
Qed.
-Lemma PI_RGT_0 : 0 < PI.
+Lemma Alt_PI_RGT_0 : 0 < Alt_PI.
Proof.
- assert (H := PI_ineq 0).
+ assert (H := Alt_PI_ineq 0).
apply Rmult_lt_reg_l with (/ 4).
apply Rinv_0_lt_compat; prove_sup0.
rewrite Rmult_0_r; rewrite Rmult_comm.