fact: Fixpoint MN_coeff (la mu : seq nat) : int := if mu is m0 :: m then foldr (fun sh acc => if ribbon sh la then MN_coeff sh m * (-1) ^+ (ribbon_height sh la).-1 + acc else acc) 0 (enum_partn (sumn m)) else 1.
imports: HB(structures) mathcomp(all_ssreflect) mathcomp(ssralg ssrint perm fingroup tuple vector rat) mathcomp(ssrcomplements freeg mpoly monalg) sorted tools ordtype permuted partition skewpart antisym Schur_mpoly Schur_altdef sympoly homogsym