In the formula in subparagraph b of the first paragraph,(a) A is the aggregate of the cost to the taxpayer of the partnership interest and of each amount required by subparagraph iv or x of paragraph i of section 255 to be added in computing the adjusted cost base to the taxpayer of the partnership interest;
(b) B is the adjusted cost base to the taxpayer of the partnership interest determined without reference to subparagraphs iv and v of paragraph l of section 257.