3 problems

Let $C$ be a triangular right coideal subalgebra of the form … Here $w_+,w_-\in W$, $\phi_+$ and $\phi_-$ are characters, $L$ is the associated lattice, $S$ is the antipode, and…

Classification conjecture. The algebra $C$ is a Borel subalgebra if and only if

Let $\mathfrak{g}=W_n$ be the Jacobson–Witt algebra of rank $n$ over the field $\mathbb{F}$, where $W_n$ is the derivation algebra of…