728.0.4. For the purposes of sections 734 and 735, any amount deducted in computing a corporation’s taxable income for a taxation year ending before 1 July 1988 in respect of a non-capital loss for another taxation year ending after 30 June 1988, is deemed to be equal to the aggregate of the amount so deducted and 1/4 of the amount by which the amount so deducted exceeds the amount by which(a) the amount deductible for the year in respect of the non-capital loss, exceeds
(b) 4/5 of the amount deductible under section 725.1.1 in computing its taxable income for the other taxation year.