An intimate connection is
established between primitive Radon partitions and generalized poonems of a set in
a real linear space ℒ. It is shown that if K ⊂ℒ is convex then K is the
convex hull of its extreme points if and only if the intersection of poonems of
K is a poonem of K. Among the applications is a study of k-neighborly
sets. This yields a considerable generalization of the theory of k-neighborly
polytopes.