OPINION OF THE COURT
Memorandum.
The order of the Appellate Division should be reversed and the judgment of the Supreme Court denying the application to stay arbitration reinstated. The board’s failure to advance a Serious argument under the Taylor Law (Civil Service Law, art 14) and the grant to the arbitrator of the "authority to decide whether the provisions of this Agreement have been complied with” mandate the conclusion that the arbitrator had jurisdiction to resolve the union’s claim that the so-called "per diem” teachers were "substitute teachers” within the terms of the agreement (see Matter of Acting Supt. of Schools of Liverpool Cent. School Dist. [United Liverpool Faculty Assn.], 42 NY2d 509, 513; Matter of South Colonie Cent. School Dist. v Longo, 43 NY2d 136; see, also, Board of Educ. v New Paltz United Teachers, 44 NY2d 890).
Chief Judge Cooke and Judges Jasen, Gabrielli, Jones, Wachtler and Fuchsberg concur.
Order reversed, with costs, and the judgment of Supreme Court, Nassau County, reinstated in a memorandum.