[math] \newcommand{\mathds}{\mathbb}[/math]

Compute the easy envelope of the general complex reflection groups

[[math]] H_N^{sd}=\left\{U\in H_N^s\Big|(\det U)^d=1\right\} [[/math]]

and of other closed subgroups of [math]U_N[/math] that you know, that are not easy.