function bigpot = multiply_by_pot(bigpot, smallpot, varargin)% MULTIPLY_BY_POT bigpot *= smallpot for cgpot% bigpot = multiply_by_pot(bigpot, smallpot)%% smallpot's domain must be a subset of bigpot's domain.bigpot = cg_mom_to_can(bigpot);smallpot = cg_mom_to_can(smallpot);mask = find_equiv_posns(smallpot.ddom, bigpot.ddom);for i=1:bigpot.dsize  if isempty(smallpot.ddom)    src = 1;  else    sub = ind2subv(bigpot.dsizes, i);    src = subv2ind(smallpot.dsizes, sub(mask));  end  bigpot.can{i} = multiply_by_pot(bigpot.can{i}, smallpot.can{src});end