U.P. Urban Buildings (Regulation of Letting, Rent and Eviction) Act (13 of 1972) , S.21(1)(b)— Proviso-Proceedings for release of building filed after period of three years as contemplated i. e. since date of purchase of building after commencement of Act - Service of notice of six months on tenant - Not required - Period contemplated for not initiating eviction under S. 21(1)(a) - Was intended to be for period of three years and in no case for more than three years and six months.Interpretation of Statutes - Harmonious interpretation. (Para 10)