2 problems

A regular CW sphere is a regular CW complex whose underlying space is a sphere, and its $cd$-index is the polynomial $\Phi_P(c,d)$ encoding its flag $f$-vector, with $c$ of degree…

Simple-polytope lower-interval conjecture. For each element $(\sigma,J)\in\mathcal W$, the lower interval $\mathcal W_{\preceq(\sigma,J)}$ is isomorphic to the face lattice of a si…