486.10. A taxpayer’s share of an original amount in respect of a specified amount paid by the taxpayer to a recipient in respect of a property is the amount that may reasonably be considered to be the taxpayer’s share of the aggregate of all amounts each of which is an amount described in section 89 or 144 in respect of the property, which share may not exceed the total of(a) the amount that is that proportion of the aggregate of all amounts each of which is an amount described in section 89 or 144 in respect of the property that the taxpayer’s share of production from the property payable to the taxpayer as a royalty, which royalty is computed without reference to the costs of exploration or production, is of the total production from the property; and
(b) the amount that is that proportion of the aggregate of all amounts each of which is an amount described in section 89 or 144 in respect of the property (other than an amount which the recipient has received or is entitled to receive as a reimbursement, contribution or allowance in respect of a royalty described in paragraph a) that the taxpayer’s share of the income from the property is of the total income from the property.