level of reduction means, in respect of a pension, one of the three amounts determined pursuant to section 26, where levels one, two and three correspond to a reduction that provides a surviving spouse with a pension that is equal to 30, 40 or 50 per cent, respectively, of a pension referred to in subparagraph 26(b)(i), if paragraph 26(b) were read without reference to supplementary benefits payable under the Supplementary Retirement Benefits Act; (niveau de réduction)