  The Fock representation of the Q-operator algebra for the diagonal WZNW model
on SU(n) at level k, where Q is the matrix of the 2D WZNW "zero modes"
generating certain dynamical quantum group, is finite dimensional and has a
natural basis labeled by su(n) Young diagrams Y of "spread" not exceeding h :=
k+n (spr (Y) = #(columns) + #(rows))
