(2)Rules made under this section may fix the minimum number of judges who are to sit for any purpose, so however that no case shall be decided by less than three judges :Provided that, if the Federal Legislature makes such provision as is mentioned in this chapter for enlarging the appellate jurisdiction of the court, the rules shall provide for the constitution of a special division of the court for the purpose of deciding all cases which would have been within the jurisdiction of the court even if its jurisdiction had not been so enlarged.
