Negative adjustment
(2) Negative adjustment(i) In general. For taxable years beginning after December 31, 1989, the alternative minimum taxable income of any taxpayer is decreased, subject to the limitation of paragraph (a)(2)(ii) of this section, by 75 percent of the excess, if any, of pre-adjustment alternative minimum taxable income (as defined in paragraph (a)(6)(i) of this section), over adjusted current earnings (as defined in paragraph (a)(6)(ii) of this section). (ii) Limitation on negative adjustments. The amount of the negative adjustment for any taxable year is limited to the excess, if any, of (A) The aggregate increases in alternative minimum taxable income in prior years under paragraph (a)(1) of this section over (B) The aggregate decreases in alternative minimum taxable income in prior years under this paragraph (a)(2).