If at any time between the nomination of the members of a court-martial and the pronouncement of sentence by that court the president dies or is otherwise unable to attend, the court shall be dissolved and the accused may be tried by another court.

The proceedings of a court-martial shall be valid notwithstanding the absence of one or more of the members other than the president, so long as the number of members present throughout the proceedings is not reduced below four:

Provided that a member of the court who has been absent for any time during a sitting shall take no further part in the proceedings.

Nothing in this section shall prejudice any power of the authority by whom a court-martial is ordered to dissolve the court