Theorem minusRoundRep : forall P, RoundedModeP b radix P -> forall p q qmp qmmp : float, (0 <= p)%R -> (p <= q)%R -> P (q - p)%R qmp -> Fbounded b p -> Fbounded b q -> exists r : float, Fbounded b r /\ r = (q - qmp)%R :>R.