Definition is_finite_strict f :=
  match f with
  | B754_finite _ _ _ _ => true
  | _ => false
  end.

(* Specifications: *)
Theorem B2R_inj: forall x y : binary_float, is_finite_strict x = true -> is_finite_strict y = true -> B2R x = B2R y -> x = y.
Theorem B2R_inj: forall x y : binary_float, is_finite_strict x = true -> is_finite_strict y = true -> B2R x = B2R y -> x = y.