Interest expense arises from the enjoyment of credit and its deductibility for
income taxes is guided by the general deduction formula interpreted using
common law. The general deduction formula is derived from section 15(2)(a) of the Income Tax
Act [Chapter 23:06], which asserts that a deduction for income tax purposes is
awarded if there is an expenditure or loss and it has been incurred for the
purposes of trade or in production of income and is not capital in nature.