2 problems

Let ${\mathcal Z}$ denote the integral coefficient ring, let ${{\mathfrak H}_{\!\vartriangle\!}(n)_{{\mathcal Z}}}$ be the integral Ringel–Hall algebra associated with the cyclic q…

Let $H_n$ be the Ringel–Hall algebra of the cyclic quiver with $n$ vertices, let $b{( u,cdots, u)}$ and b{( u,cdots, u)}^ denote the canonical and dual canonical basis elements i…