In calculating an amount that may be included in assessable income:
(a) an element in the calculation that is an amount received or receivable is treated as not including an amount equal to any * GST payable on a * taxable supply related to the amount received or receivable, or any * increasing adjustment related to that amount; and
(b) an element in the calculation that is an amount paid or payable is treated as not including an amount equal to any * input tax credit for an * acquisition related to the amount paid or payable, or any * decreasing adjustment related to that amount.