proposition: Lemma list_of_posK: cancel list_of_pos pos_of_list.
proof: Proof. by elim => // p /= -> ;case: p. Qed.
imports: mathcomp(ssreflect ssrfun ssrbool eqtype ssrnat) mathcomp(seq choice fintype order bigop ssralg) mathcomp(div ssrnum ssrint rat prime path binomial) mathcomp(tuple finset) gaia(fibm)