  The article deals with operations defined on convex polyhedra or polyhedral
convex functions. Given two convex polyhedra, operations like Minkowski sum,
intersection and closed convex hull of the union are considered. Basic
operations for one convex polyhedron are, for example, the polar, the conical
hull and the image under affine transformation. The concept of a
P-representation of a convex polyhedron is introduced. It is shown that many
polyhedral calculus operations can be expressed explicitly in terms of
P-representations. We point out that all the relevant computational effort for
polyhedral calculus consists in computing projections of convex polyhedra. In
order to compute projections we use a recent result saying that multiple
objective linear programming (MOLP) is equivalent to the polyhedral projection
problem. Based on the MOLP-solver bensolve a polyhedral calculus toolbox for
Matlab and GNU Octave is developed. Some numerical experiments are discussed.
