Cospanning characterizations of antimatroids and convex geometries

Kempner Yulia, Vadim E. Levit

Given a finite set $E$ and an operator $\sigma :2^E⟶2^E$, two sets $X,Y\subseteq E$ are \textit{cospanning} if $\sigma \left(X\right)=\sigma \left(Y\right)$. Corresponding \tex…