For $m$ a non-negative integer and $G$ a Coxeter group. we denote by $\mathbf{QI_m}(G)$ the ring of $m$-quasiinvariants of $G$. as defined by Chalykh. Feigin. https://www.ivoryjinelle.com/top-offer-Dragon-Ball-Super-Goku-Vegeta-Super-Ball-LG-Stylo-6-Clear-Case-p103191-quick-deal/