(concurring).
I quite agree with the court’s opinion, but with the understanding, of which I wish to make note, that we are not presently deciding whether, if the strike was an unfair labor practice, it would be contrary to the provisions of the Act to foreclose by contract an employer’s right to take the action contemplated by section 8(d) (4). Cf. Penello v. International Union, U.M.W., D.C.D.C., 1950, 88 F. Supp. 935, 941; see Local 453, International Union of Elec. Workers v. Otis Elevator Co., 2 Cir., 1963, 314 F.2d 25, cert. den. 373 U.S. 949, 83 S.Ct. 1680, 10 L.Ed.2d 705. I note, also, that a deter-/ mination by the arbitrator, as a prelude to granting relief under the contract] that the strike was not an unlawful laboit practice would not be final. See Carey v. Westinghouse Corp., 1964, 375 U.S. 261, 272, 84 S.Ct. 401, 11 L.Ed.2d 320.