792.1. Where, in a taxation year ending after 31 December 1985, all or a portion of a patronage dividend made by a taxpayer to his customers who are members is not deductible in computing his income for the year because of the application of subsection 1 of section 792, in this section referred to as the "undeducted portion", the taxpayer may deduct, in computing his income for a subsequent taxation year, an amount equal to the lesser of(a) the undeducted portion, except to the extent that that portion was deducted in computing his income for any preceding taxation year; and
(b) the amount by which the taxpayer’s income for the subsequent taxation year, computed without reference to this section, attributable to business done with his customers of that year who are members exceeds the amount deducted in computing his income for the subsequent taxation year by virtue of section 786 in respect of patronage dividends made by him to his customers of that year who are members.