fact: Definition catlang d1 d2 (s1 : homlang d1) (s2 : homlang d2) : homlang (d1 + d2) := [set cat_tuple w1 w2 | w1 in s1, w2 in s2].
imports: HB(structures) mathcomp(all_ssreflect) mathcomp(ssralg) mathcomp(ssrcomplements freeg mpoly) tools ordtype partition Yamanouchi std tableau stdtab Schensted congr plactic stdplact Yam_plact Greene_inv shuffle Schur_mpoly