An edge e = (u, v, o) can be broken down into a source u ∈ V , and a destination (v, o) ∈ V × 3 . The source can be seen as the vertex of identifier u and positioned in the cell at the origin of the lattice, and the destination is the vertex to which it is linked. When the source and the destination are in the same cell, the offset o is zero and noted 0 3 = (0, 0, 0). Edges of the form (u, u, 0 3 ), called loops, are absent in nets because they do not convey any structural information.