517.3.1. The aggregate referred to in the second instance in section 517.2 is the sum of(a) the greater ofi. the paid-up capital, immediately before the disposition, in respect of the subject shares, and
ii. subject to sections 517.4 to 517.4.2, the adjusted cost base to the taxpayer, immediately before the disposition, of the subject shares;
(b) the aggregate of all amounts required to be deducted by the purchaser corporation under paragraph a of subsection 1 of section 84.1 of the Income Tax Act (Revised Statutes of Canada, 1985, chapter 1, 5th Supplement) in computing the paid-up capital in respect of any class of shares of its capital stock by virtue of the acquisition of the subject shares.