intros p q H' H'0 H'1.
rewrite
(FcanonicUnique _ radixMoreThanOne b precision) with (p := p) (q := q);
auto with arith.
Qed.

Theorem FweightZle :
forall p q : float,
Fcanonic radix b p ->
Fcanonic radix b q -> (0 <= p)%R -> (p <= q)%R -> (Fweight p <= Fweight q)%Z.