"(2)... a court shall be duly constituted for the purposes of exercising any of its jurisdiction if it consists of any uneven number of judges not less than three... (4)...a court shall, if it consists of two judges, be duly constituted for every purpose except- (a) determining an appeal against (i) conviction..."
"An appeal is 'determined' for the purposes of section 55 when the decision is properly to be treated as binding on the judges themselves."