proposition: Lemma ZeckP l: sorted ggen l -> Zeck (Zeck_val l) = l.
proof: Proof. move => h. by apply: (Zeck2_unique (Zeck_ggen (Zeck_val l)) h); rewrite Zeck_zeck_val. Qed.
imports: mathcomp(ssreflect ssrfun ssrbool eqtype ssrnat) mathcomp(seq path fintype div bigop binomial) mathcomp(prime finset ssralg ssrnum ssrint)