law: The Assam Reorganisation (Meghalaya) Act, 1969
  Disqualifications of members
  28. Vacation of seats.-
  (1) No person shall be a member of Parliament or of the Legislative Assembly of the State of Assam and also of the Legislative Assembly of Meghalaya, and if a person is chosen a member of Parliament or of the Legislative Assembly of Assam and also of the Legislative Assembly of Meghalaya, then, at the expiration of such period, as may be specified in rules made by the President, that person's seat in Parliament or, as the case may be, in the Legislative Assembly of Assam, shall become vacant unless he has previously resigned his seat in the Legislative Assembly of Meghalaya.
  (2) If a member of the Legislative Assembly-
  (a) becomes subject to any of the disqualifications mentioned in section 29, or
  (b) resigns his seat by writing under his hand addressed to the Speaker, his seat shall thereupon become vacant.
  (3) If for a period of sixty days a member of the Legislative Assembly is, without permission of the Legislative Assembly, absent from all meetings thereof, the Assembly may declare his seat vacant:
  Provided that in computing the said period of sixty days no account shall be taken of any period during which the Legislative Assembly is prorogued or is adjourned for more than four consecutive days.