2 problems

Let $M$ be an $n$-dimensional compact Alexandrov space with nonnegative curvature, and let $\tau_n$ denote the number of extremal subsets of $M$. Extremal-subset counting conjectur…

Primitive extremal subset conjecture. Every primitive extremal subset of an Alexandrov space, equipped with its induced intrinsic metric, should be an Alexandrov space with the sam…