isNormal can only be applied to polytopes, i.e. compact polyhedra. It embeds the polytope on height 1 in a space of dimension plus 1 and takes the Cone over this polytope. Then it checks if all elements of the Hilbert basis lie in height 1.
i1 : P = convexHull transpose matrix {{0,0,0},{1,0,0},{0,1,0},{1,1,3}} o1 = P o1 : Polyhedron |
i2 : isNormal P o2 = false |