弱いPBW定理: 整列単項式は普遍被覆代数を生成する

theorem UniversalEnvelopingAlgebra.pbw_span {m : Type u_1} {R : Type u_2} {L : Type u_3} [LinearOrder m] [CommRing R] [LieRing L] [LieAlgebra R L] (B : Module.Basis m R L) : Submodule.span R (List.prod ∘ List.map (⇑(ι R) ∘ ⇑B) '' {l : List m | l.SortedLE}) = ⊤