The previously attributed input tax credit amount for an acquisition is:
(a) the amount of any input tax credit that was attributable to a tax period in respect of the acquisition; minus
(b) the sum of any * increasing adjustments, under this Subdivision or Division 21, 129, 131 or 134, that were previously attributable to a tax period in respect of the acquisition; plus
(c) the sum of any * decreasing adjustments, under this Subdivision or Division 21, 129 or 133, that were previously attributable to a tax period in respect of the acquisition.