360R84. In this division, the additional depletion of a taxpayer at a particular time means an amount equal to the amount by which the aggregate of the following amounts exceeds the amount computed under section 360R85 at that time:(a) 50% of the expenses incurred by the taxpayer before that time, each of which was the capital cost to the taxpayer of a property that is primary recovery equipment;
(b) 33 1/3% of the expenses incurred by the taxpayer before that time, each of which was the capital cost to the taxpayer of a property that is bituminous sands equipment acquired before 1 January 1981 and which, before it was acquired by the taxpayer, had not been used by any person with whom the taxpayer was not dealing at arm’s length; and
(c) where the taxpayer is a corporation referred to in section 360R87, any amount required by paragraph a of that section to be added before that time in computing its additional depletion.