proposition: Lemma msuppU_le {k x} : msupp << x *g k >> `<=` [fset k].
proof: Proof. by rewrite msuppU; case: eqP. Qed.
imports: HB(structures) mathcomp(ssreflect ssrfun ssrbool eqtype ssrnat) mathcomp(seq path choice finset fintype finfun) mathcomp(tuple bigop ssralg ssrint ssrnum) xfinmap