proposition: Lemma G3_c (n: nat): #|[set f:Ftype 0 n | monomial_le f ]| = 1.
proof: Proof. set f0: (Ftype 0 n):= [ffun _ => ord0]. apply /eqP/cards1P; exists f0; rewrite -setP => g; rewrite in_set1 in_set. by apply/eqP; case:ifP; [ rewrite big_ord0 | case/eqP /ffunP; case]. Qed.
imports: mathcomp(ssreflect ssrfun ssrbool eqtype) mathcomp(ssrnat seq path div) mathcomp(fintype tuple finfun bigop finset binomial)