(1) In this section -
'chargeable period' has the same meaning as in section 321(2);
'emoluments', 'employment', 'employment scheme', 'qualifying employment', and 'qualifying individual' have the same meanings, respectively, as in section 472A;
'qualifying period', in relation to a qualifying employment, means the period of 36 months beginning on the date when that employment commences.
(a) Where in the computation of the amount of the profits or gains of a trade or profession for a chargeable period, a person is, apart from this section, entitled to a deduction (in this subsection referred to as 'the first-mentioned deduction') on account of -
(i) emoluments payable to a qualifying individual in respect of a qualifying employment, and
(ii) the employer's contribution to the Social Insurance Fund payable, in respect of those emoluments, under the Social Welfare Acts,
that person shall be entitled in that computation to a further deduction (in this subsection referred to as 'th