fact: Fixpoint Dyck_of_bintree t := if t is BinNode l r then [Dyck {{ (Dyck_of_bintree l) }} Dyck_of_bintree r] else nil_Dyck.
imports: HB(structures) mathcomp(all_ssreflect) mathcomp(div ssralg ssrint ssrnum binomial) tools combclass bintree