Judgment reversed, on the law, without costs or disbursements, and application denied.
The arbitrator's reliance on evidence of appellant's office practice and mailing procedure in his determination of the issue of mailing under section 313 of the Vehicle and Traffic Law was not wholly irrational and was therefore not a ground for vacatur of the award under the prevailing standard of review for compulsory arbitration (see Matter of Garcia v Federal Ins. Co., 46 N.Y.2d 1040; cf. Mount St. Mary's Hosp. of Niagara Falls v Catherwood, 26 N.Y.2d 493; Caso v Coffey, 41 N.Y.2d 153). Furthermore, the arbitrator did not exceed his power by finding that coverage was terminated on July 3, 1977, rather than on April 3, 1977, the termination date originally asserted by appellant. The scope of the controversy submitted to arbitration is governed by the demand for arbitration, which, in this case, indicates that the issue to be resolved was the general question of the insured's coverage as of the date of the accident, September 11, 1977.