13.—(1) Any one, two or three of the Special Commissioners shall constitute a Tribunal.
(2) Where any proceedings are before a Tribunal which comprises two or three Special Commissioners—
(a)if the Presiding Special Commissioner is one of them, he shall preside at the hearing unless he otherwise directs and, if he is not, one of them shall be nominated by him to preside;
(b)the proceedings may be continued by any one or more of them if all the parties give their consent and unless the Presiding Special Commissioner otherwise directs.