336.6. An individual, other than a trust that is not a personal trust, may deduct in computing the individual’s income for a particular taxation year the unused portions of the total investment expense of the individual for the taxation years that precede the particular year and those for the three taxation years that follow the particular year, up to the amount by which the amount of the individual’s investment income for the particular year exceeds the individual’s total investment expense for the particular year.
However, for the purpose of computing the individual’s income for the taxation year in which the individual died and for the preceding taxation year, the first paragraph is to be read as if “for the taxation years that precede the particular year and those for the three taxation years that follow the particular year, up to the amount by which the amount of the individual’s investment income for the particular year exceeds the individual’s total investment expense for the particular year” was replaced by “for all of the individual’s taxation years”.