(3)A person who has received discharge under this section shall not be required to render national service after such discharge:Provided that a person who has received discharge under this section before he has completed four years of national service, shall, unless he has ceased to be liable to be called up for national service under this Act, be liable to be called up for national service under this Act for such term as will, together with the period of national service rendered by him, be equivalent to four years.
