76. For the purpose of computing, at any particular time after 1971, the adjusted cost base to a taxpayer of an interest in a partnership of which he was a member on 31 December 1971 and thereafter without interruption until that time, the cost to him of the interest shall be deemed to be the amount that is neither the greatest nor the least of the following three amounts, namely:
(a) the actual cost of the interest to the taxpayer at that time;
(b) the amount determined under section 77 at that time; and
(c) the amount by which the aggregate of the fair market value of the interest at that time and the amounts required by section 257 of the Taxation Act (chapter I-3) to be deducted in computing the adjusted cost base to the taxpayer immediately before the particular time exceeds the aggregate of the amounts required by section 255 of the said Act to be included in that computation at the same time.
However, if two or more of the amounts determined under paragraphs a to c are the same, that amount is deemed to be the cost of that interest to the taxpayer.