  A finite irreducible real reflection group of rank l and Coxeter number h has
root system of cardinality h*l. It is shown that the fake degree for the
permutation action on its roots is divisible by [h]_q = 1+q+q^2+...+q^{h-1},
and that in simply-laced types, it equals [h]_q times the summation of q^{e_i -
1} where e_i runs through the exponents, so that e_i - 1 are the codegrees.
