Income tax and super tax (1) Subject to the provisions of sub section (2), (3), (4) and (5), for the assessment year commencing on the 1st day of April, 1963, (a) income tax shall be charged at the rates specified in Part I of the First Schedule and, (i) in the cases to which paragraphs A,C,C and E of that Part apply, shall be increased by a surcharge for purposes of the Union and, except in the cases to which the said paragraph applies a special surcharge, calculated in either case in the manner provided therein; and (ii) in the cases to which paragraphs A and of the aforesaid Part apply, shall further be increased by an additional surcharge for purposes of the Union (hereinafter referred to as additional surcharge) calculated in the manner provided in the said Schedule;" Section 2 (8) provides that: For the purposes of paragraphs A and of Part I of the First Schedule, the expression "residual income" means the amount of the total income as reduced by 140 (a) the amount of the capital gains, if any, included therein; and (b) the amount of tax (exclusive of additional surcharge) which would have been chargeable on such reduced total income if it had been the total income no part of which had been exempt from tax and on no portion of which deduction of tax had been admissible under any provisions of the Income tax Act or this Act.