S.37(1): Business expenditure Prior period expenditure-Expenditure crystallising only during relevant previous year when bills were received-Allowable as deduction-Provisions for expenses at end of previous year-Actually paid after end of previous year-Allowable as deduction-Contributions to provident Funds-Provision for gratuity-Government Provident Fund Established as Per Provident Funds Act, 1925-Allowable as deduction. [S. 36(1)(va) 40A(7) 145, Constitution, Art.12]