accumulated basic contributions

, in relation to a person who has ceased to be an eligible employee, means an amount equal to the sum of the basic contributions that have been, or are deemed to have been, paid, or have become payable, by him or her on or after his or her first day of service and the amount of any interest on those contributions together with, in the case of a person who had previously ceased to be an eligible employee on an occasion earlier than his or her first day of service, any amount that, under section 7A, is to be added to the amount of his or her accumulated basic contributions.