Integral Polyhedra in Three Space

In a series of recent papers I have introduced a particular class of convex polyhedra in Rⁿ, arising in the study of integer programming problems with n variables. In the present paper a detailed analysis of these polyhedra will be given for the case in which n = 3; the analysis is based on an unpublished theorem demonstrated several years ago by Roger Howe, which seems to have no immediate generalization to higher values of n.