intros p q H' H'0 H'1; case H'; case H'0; intros H'2 H'3.
apply FnormalUnique; auto.
Contradict H'1; apply NormalAndSubNormalNotEq; auto.
absurd (q = p :>R); auto; apply NormalAndSubNormalNotEq; auto.
apply FsubnormalUnique; auto.
Qed.

Theorem FcanonicLeastExp :
forall x y : float,
x = y :>R -> Fbounded b x -> Fcanonic y -> (Fexp y <= Fexp x)%Z.