For the purposes of this Act:
(a) a military commission of the United States of America is taken to be a court or tribunal of the United States of America; and
(b) any punishment or measure involving deprivation of liberty ordered by a military commission of the United States of America is taken to have been ordered by a court or tribunal of the United States of America in the exercise of its criminal jurisdiction; and
(c) any direction or order given or made by a military commission of the United States of America with respect to the commencement of such punishment or measure is taken to have been given or made by a court or tribunal of the United States of America.