Computation of profits for mineral oil and natural gas: defines gross income, allowable business expenditures, and treatment of negative profits. Computation of profits for the business of mineral oil or natural gas requires gross income from business activities reduced by business expenditure wholly and exclusively for business purposes; gross income includes receipts from core operations, leasing or transfer of oil or gas rights and business assets, and disposals of capital assets where deductions are or would be allowable. Allowable deductions include operating expenditure, permitted finance charges, licence and rental charges actually paid, land or land-rights costs, capital expenditure, abortive exploration expenses, pre-commencement expenditures and prior-year negative profits. Negative computed profits are treated as nil.