Computes a skew Kostka-Foulkes polynomial.
SkewKostkaFoulkesPolynomial(lambda, mu, nu)The skew Kostka-Foulkes polynomial associated to the skew
partitiion defined by lambda and mu and to the partition
nu. This is a univariate qspray polynomial whose value
at 1 is the skew Kostka number associated to the skew partition
defined by lambda and mu and to the partition nu.
integer partitions defining the skew partition:
lambda is the outer partition and mu is the inner partition
(so mu must be a subpartition of lambda)
integer partition; the condition
sum(nu)==sum(lambda)-sum(mu) is necessary in order to get a
non-zero polynomial