  We provide an introduction to a very specific toy model of memristive
networks, for which an exact differential equation for the internal memory
which contains the Kirchhoff laws is known. In particular, we highlight how the
circuit topology enters the dynamics via an analysis of directed graph. We try
to highlight in particular the connection between the asymptotic states of
memristors and the Ising model, and the relation to the dynamics and statics of
disordered systems.
