2 problems

Let $H$ be a free abelian group, let $L'(H)$ be the free quasi-Lie algebra on $H$, and let $\mathcal A_k^t(H)$ be the abelian group generated by labelled planar binary trees of the…

Let $H$ be a free abelian group, and let $L(H)$ and $L'(H)$ denote the free Lie algebra and free quasi-Lie algebra on $H$, respectively. For $l\geq 1$, write $L_l(H)$ and…