Generalize negative_or_positive.

788027d2 · Guillaume Melquiond · 56ac17d0 · 788027d2 · 788027d2
Commit 788027d2 authored Feb 28, 2017 by Guillaume Melquiond
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lib/coq/ieee_float/GenericFloat.v lib/coq/ieee_float/GenericFloat.v +2 -2

theories/ieee_float.why theories/ieee_float.why +4 -2

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--- a/lib/coq/ieee_float/GenericFloat.v
+++ b/lib/coq/ieee_float/GenericFloat.v
@@ -1604,10 +1604,10 @@ destruct x, b; easy.
 Qed.

 (* Why3 goal *)
-Lemma negative_or_positive : forall (x:t), (is_finite x) -> ((is_positive
+Lemma negative_or_positive : forall (x:t), (is_not_nan x) -> ((is_positive
  x) \/ (is_negative x)).
 intros x h1.
-destruct x, b; simpl; auto; easy.
+destruct x, b; simpl; auto; now elim h1.
 Qed.

 (* Why3 goal *)

--- a/theories/ieee_float.why
+++ b/theories/ieee_float.why
@@ -340,8 +340,10 @@ theory GenericFloat
  axiom to_real_negative: forall x [is_negative x].
    is_finite x -> to_real x <. 0.0 -> is_negative x

-  axiom negative_xor_positive: forall x. not (is_positive x /\ is_negative x)
-  axiom negative_or_positive: forall x. is_finite x -> is_positive x \/ is_negative x
+  axiom negative_xor_positive: forall x.
+    not (is_positive x /\ is_negative x)
+  axiom negative_or_positive: forall x.
+    is_not_nan x -> is_positive x \/ is_negative x

  lemma diff_sign_trans:
    forall x y z:t. (diff_sign x y /\ diff_sign y z) -> same_sign x z