diff options
author | bertot <bertot@85f007b7-540e-0410-9357-904b9bb8a0f7> | 2012-06-05 12:17:32 +0000 |
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committer | bertot <bertot@85f007b7-540e-0410-9357-904b9bb8a0f7> | 2012-06-05 12:17:32 +0000 |
commit | 9dea6a7404a251dbf7c467b445aca2686de59d22 (patch) | |
tree | 765772817c26d94ed5af763cda7bc4ee763644b1 /theories/Reals/AltSeries.v | |
parent | 83b88cee6a66f999a4198200eade41ef49f038c6 (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.v | 12 |
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. |