fact: Definition T1 := (T :&: [set j : 'I_(size x) | j <= posb]) :|: (S :&: [set j : 'I_(size x) | j >= posc]).
imports: mathcomp(all_ssreflect) mathcomp(perm) tools ordcast ordtype subseq partition tableau Yamanouchi stdtab Schensted congr plactic Greene