fact: Fixpoint encode_tree l k (t : tree l k) : GenTree.tree unit := match t with | Frontier _ => GenTree.Leaf tt | Node _ _ s => GenTree.Node 0 (map (@encode_tree _ _) s) end.
imports: mathcomp(all_ssreflect ssralg fingroup zmodp poly ssrnum) mathcomp(matrix perm) ssr_ext ssralg_ext fdist