261. Except where section 261.1 applies, where the aggregate of all amounts required by section 257, except paragraph l of that section, to be deducted in computing the adjusted cost base to a taxpayer of any property at any time in a taxation year exceeds the aggregate of the cost to the taxpayer of the property determined for the purpose of computing the adjusted cost base to the taxpayer of that property at that time and of all amounts required by section 255 to be added to the cost to the taxpayer of the property in computing the adjusted cost base to the taxpayer of that property at that time, the following rules apply:(a) subject to section 589.1, the amount of the excess is deemed to be a gain of the taxpayer for the year from the disposition at that time of the property;
(b) for the purposes of Chapter V of Title X and sections 1102.4 and 1102.5, the taxpayer is deemed to have disposed of the property at that time; and
(c) for the purposes of section 26, the first paragraph of section 27, Title VI.5 of Book IV and sections 1000 to 1003.2, the taxpayer is deemed to have disposed of the property in the year.