(4)[ The Central Government may appoint one or more members of the Appellate Tribunal to be the Vice-President or, as the case may be, Vice-Presidents thereof.] [Inserted by Act 16 of 1972, Section 40 (w.r.e.f. 1.4.1972).][(4-A) The Central Government may appoint one of the Vice-Presidents of the Appellate Tribunal to be the Senior Vice-President thereof.] [ Inserted by Act 21 of 1984, Section 24 (w.r.e.f. 1.4.1984).]