Gift-tax interpretation treats 'such tax' as the tax chargeable reduced by the allowable credit under the Act. Clause (i) of sub-section (1) of section 17 of the Gift-tax Act, as it stood before 1 April 1963, shall be deemed to have effect as if the words 'such tax' mean the gift-tax chargeable under the Act as reduced by the amount for which credit is allowed under the Act.