Where this Chapter applies to an individual for a tax year, notwithstanding anything in any provision of the Tax Acts other than this Chapter, the individual's taxable income for the tax year shall, instead of being the amount it would have been had this Chapter not applied to the individual for the tax year, be the amount determined by the formula -

T + (S – Y)

where -

T is the amount of the individual's taxable income for the tax year determined on the basis that this Chapter, other than sections 485F and 485FA, does not apply to the individual for the tax year,

S is the aggregate of the specified reliefs for the tax year, and

Y is the greater of -

(i) the relief threshold amount, and

(ii) 20 per cent of the individual's adjusted income for the tax year.