intros H; left; auto with float.
apply FnormalFabs; auto.
intros H; right; auto with float.
apply FsubnormFabs; auto.
Qed.

Theorem NormalNotSubNormal : forall p : float, ~ (Fnormal p /\ Fsubnormal p).
intros p; red in |- *; intros H; elim H; intros H0 H1; clear H.