Definition Fweight (p : float) :=
  (Fnum p + Fexp p * Zpower_nat radix precision)%Z.

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.