that yields a so-called topological genome of the net, which is a finite series of numbers. This genome is provably unique for each net, only depends on the net itself and not its representation, and can be computed in polynomial time of the size of the net. To do so, Systre starts by computing an equilibrium placement of the vertices, which attributes to each vertex a position which is the barycentre of that of its neighbours. The net is then minimised, which amounts to finding a unit cell. Afterwards, Systre collects a number of candidates, which are frames of reference that do not depend on the current representation of the net. For each candidate, the vertices of the net are ordered according to their position in the frame of reference, and a key is determined which uniquely identifies the net with this ordering in this frame. The genome is then chosen as the lexicographically smallest key. Since the candidates do not depend on the initial representation of the graph, the keys do not either, hence the genome is indeed uniquely determined and only depends on the net itself. In graph theory, the problem Systre solves is called graph canonization. It incidentally allows determining whether two input graphs are actually two representations of the same graph (the graph isomorphism problem) by comparing their canonical forms (here, the genome), but it can also be used to give a canonical name to graphs for example, by accessing a database of names with the canonical form of the graphs.