aboutsummaryrefslogtreecommitdiffstats
path: root/flocq/Core/Fcore_float_prop.v
diff options
context:
space:
mode:
Diffstat (limited to 'flocq/Core/Fcore_float_prop.v')
-rw-r--r--flocq/Core/Fcore_float_prop.v31
1 files changed, 31 insertions, 0 deletions
diff --git a/flocq/Core/Fcore_float_prop.v b/flocq/Core/Fcore_float_prop.v
index e1535bc9..8199ede6 100644
--- a/flocq/Core/Fcore_float_prop.v
+++ b/flocq/Core/Fcore_float_prop.v
@@ -233,6 +233,37 @@ rewrite <- F2R_0 with (Fexp f).
now apply F2R_lt_compat.
Qed.
+Theorem F2R_neq_0_compat :
+ forall f : float beta,
+ (Fnum f <> 0)%Z ->
+ (F2R f <> 0)%R.
+Proof.
+intros f H H1.
+apply H.
+now apply F2R_eq_0_reg with (Fexp f).
+Qed.
+
+
+Lemma Fnum_ge_0_compat: forall (f : float beta),
+ (0 <= F2R f)%R -> (0 <= Fnum f)%Z.
+Proof.
+intros f H.
+case (Zle_or_lt 0 (Fnum f)); trivial.
+intros H1; contradict H.
+apply Rlt_not_le.
+now apply F2R_lt_0_compat.
+Qed.
+
+Lemma Fnum_le_0_compat: forall (f : float beta),
+ (F2R f <= 0)%R -> (Fnum f <= 0)%Z.
+Proof.
+intros f H.
+case (Zle_or_lt (Fnum f) 0); trivial.
+intros H1; contradict H.
+apply Rlt_not_le.
+now apply F2R_gt_0_compat.
+Qed.
+
(** Floats and bpow *)
Theorem F2R_bpow :
forall e : Z,