Firstly, let’s consider another type of roof, that is, standard roof.
For subset A of standard lattice L3, Roof A is a set of points (l, m, n) in R3 which satisfy …
As shown below, Roof* A is obtained by putting as …
Shown on the left is a standard cone generated by three peaks, x1l+1x2mx3n, x1lx2m+2x3n, and x1l+1x2mx3n+1. And, by putting two cubes on the cone, we obtain the roof, shown on the right, which is equal to Cone { x1lx2mx3n }.