16.18. Where an operator is a partnership that incurs expenses referred to in subparagraph a of subparagraph 1 of the second paragraph of section 16.9, the expenses relating to the share, described in paragraph d of section 395 of the Taxation Act (chapter I-3), which is attributed to each partner of the operator are deemed, from the day on which they are incurred, never to have been such expenses incurred by the operator. The first paragraph does not apply to the expenses which are attributed by the operator to a partner that is a legal person if the legal person gives an undertaking in writing to the Minister not to renounce, under the Taxation Act or the Income Tax Act (R.S.C. 1985, c. 1, (5th Suppl.)), those expenses and the legal person fulfills that undertaking.