2026-07-072026-07-07http://salesiana.dossiersoluciones.com/handle/123456789/89904We consider the set of all matrices of the form $p_{ij}=tr[W(E_{i}\otimes F_{j})]$ where $E_{i}$, $F_{j}$ are projections on a Hilbert space $H$, and $W$ is some state on $H\otimes H$. We derive the basic properties of this set, compare it with the classical range of probability, and note how its properties may be related to geometric measures of entanglement.8 pages, contribution to proceedings of the conference "Quantum Theory: Reconsideration of Foundations", Vaxjo, July 2001Quantum Physicstext