In addition, discrete graphs make it possible to handle the anisotropy problem as well. It is sufficient to introduce an element of randomness in the network by, e.g., taking averages over a connected set of nodes, to avoid any privileged directions. There are clearly similarities here with the irregular tiling scheme or the introduction of vagueness, but the important distinction is that statistical and probabilistic concepts are (fairly) well understood, whereas the tiling problem is, as mentioned, an open problem, and vagueness remains a notoriously difficult concept to grasp (see the entry on vagueness in this encyclopedia).