Order for the issuance of the writ of mandamus reversed. Case remanded to the Superior Court with directions to dismiss the petition. This is a petition for a writ of mandamus by six residents of the town of Belmont to compel the inspector of buildings of the town to revoke a building permit, or, in the alternative, to enforce the zoning laws of the town so as to prevent an alleged illegal use in a single residence district. The court below ordered the writ to issue revoking the permit, and from this order the respondent appealed. G. L. c. 213, § ID, as amended by St. 1957, c. 155. At the arguments in this court we were in*774formed by affidavit that the premises covered by the permit have been sold and are now being used for a purpose permitted by the town’s zoning laws. The petitioners suggest that the case is now moot, and we agree. The order for the issuance of the writ, therefore, is reversed, not on the merits, but because the case has become moot, and the case is remanded to the Superior Court with directions to dismiss the petition. See Vigoda v. Superintendent of Boston State Hosp. 336 Mass. 724.