  This paper studies two related subjects. One is some combinatorics arising
from linear projections of polytopes and fans of cones. The other is quotient
varieties of toric varieties. The relation is that projections of polytopes are
related to quotients of projective toric varieties and projection of fans are
related to quotients of general toric varieties. Despite its relation to
geometry the first part is purely combinatorial and should be of interest in
its own right.
