77. The amount contemplated in paragraph b of section 76 in respect of a taxpayer at a particular time is the amount by which the aggregate computed under section 78 is exceeded by:(a) his share, determined at the commencement of the first fiscal period of the partnership ending after 1971, of the tax equity of the partnership at that time;
(b) such part of any contribution of capital made by the taxpayer to the partnership, otherwise than by way of loan, before 1972 and after the commencement of the partnership’s first fiscal period ending after 1971, as cannot reasonably be regarded as a gift made to, or for the benefit of, any other member of the partnership related to the taxpayer; and
(c) the amount of any consideration that became payable by the taxpayer after 1971 to any other person to acquire, after 1971, any right in respect of the partnership, the sole purpose of the acquisition of which was to increase his interest in the partnership.