2 problems

Let $\mathfrak g$ be a reductive Lie algebra, let $\mathfrak p$ be a parabolic subalgebra of $\mathfrak g$, and let $\mathfrak p^{\sf nil}$ denote its nilpotent radical. Write…

Let $\Phi\subset\Delta^+$ be such that $\mathfrak{g}^{\Phi}$ is an ad-nilpotent ideal of $\mathfrak{g}$. An H-sequence $\mathbf{h}$ of $\Delta^+\setminus\Phi$ is a sequence used to…