The lattices of matroid bases and exact matroid bases (Q1176781)

Combinatorial objects are often associated with the polytope generated by the incidence vectors of the objects. The lattice of these incidence vectors is the set of all of their integer combinations. Such lattices are described if the objects are the bases of a matroid on \(E\), or only those bases which contain exactly \(p\) elements of a given subset \(R\subseteq E\).