Definition is_finite f :=
  match f with
  | B754_finite _ _ _ _ => true
  | B754_zero _ => true
  | _ => false
  end.Definition is_finite_FF f :=
  match f with
  | F754_finite _ _ _ => true
  | F754_zero _ => true
  | _ => false
  end.

Theorem B2R_Bsign_inj: forall x y : binary_float, is_finite x = true -> is_finite y = true -> B2R x = B2R y -> Bsign x = Bsign y -> x = y.