156.7.3. In computing a taxpayer’s income for a taxation year from a business, there may be deducted an amount equal to 50% of the aggregate of all amounts each of which is the portion of the amount deducted in computing the taxpayer’s income for the year under paragraph a of section 130 or the second paragraph of section 130.1, in respect of the taxpayer’s prescribed depreciable property, that relates to the cost of eligible work.