Editing Hyperplane (section)

===Support hyperplanes===
A hyperplane H is called a "support" hyperplane of the polyhedron P if P is contained in one of the two closed half-spaces bounded by H and <math>H\cap P \neq \varnothing</math>.<ref>Polytopes, Rings and K-Theory by Bruns-Gubeladze</ref> The intersection of P and H is defined to be a "face" of the polyhedron. The theory of polyhedra and the dimension of the faces are analyzed by looking at these intersections involving hyperplanes.