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

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