158.5. For the purposes of this division, the following rules apply:(a) where a taxpayer’s matchable expenditure is made before the day on which the related right to receive production is acquired by the taxpayer, the expenditure is deemed to have been made on that day;
(b) where a taxpayer has one or more rights to renew a particular right to receive production to which a matchable expenditure relates for one or more additional terms, after the term that includes the time at which the particular right was acquired, the particular right is deemed to terminate on the latest day on which the latest possible such term could terminate if all rights to renew the particular right were exercised;
(c) where a taxpayer has more than one right to receive production that can reasonably be considered to be related to each other, the rights are deemed to be one right; and
(d) where the term of a taxpayer’s right to receive production is for an indeterminate period, the right is deemed to terminate 20 years after it is acquired.