discussed Cited "see, e.g." Local 710, International Brotherhood of Teamsters v. Montgomery Ward & Co. See, e.g., Edward Hines Lumber Co. v. Lumber & Sawmill Workers, 764 F.2d 631, 635 (9th Cir. 1985) (arbitrator may find that, despite lack of express prohibition on subcontracting, other substantive provisions of contract give rise to implied restrictions) cert. denied, 475 U.S. 1131 , 106 S.Ct. 1661 , 90 L.Ed.2d 203 (1986); International Union, United Automobile, Etc. v. Webster Electric Co., 299 F.2d 195, 197 (7th Cir.1962) (subcontracting "inconsistent with the basic purpose” of contract containing a union shop provision).