484.7. For the purposes of this subdivision, “specified cost” to a person of a debt owing to the person means(a) where the debt is capital property of the person, the adjusted cost base to the person of the capital property; and
(b) in any other case, the amount by which the cost amount to the person of the debt exceeds such portion of that cost amount as would be deductible in computing the person’s income, otherwise than in respect of the principal amount of the debt, if the debt were established by the person to have become a bad debt.