proposition: Lemma sorted_gtn l: uniq l -> sorted gtn (rev (sort leq l)).
proof: Proof. rewrite rev_sorted ltn_sorted_uniq_leq sort_uniq (sort_sorted leq_total) => ->. done. Qed.
imports: mathcomp(ssreflect ssrfun ssrbool eqtype ssrnat) mathcomp(seq path fintype div bigop binomial) mathcomp(prime finset ssralg ssrnum ssrint)