Singularity interactions for lattice equations: introducing the taishi

We study the singularities of some selected integrable lattice equations and show they all admit three types of singularities: one of finite and two of infinite extent.

In particular, we show that all the equations we study possess a recently discovered, strip-like, singularity which is known under the moniker of ''taishi''.

We study in detail the interaction of these taishi with the remaining two types of singularities and show that the rich behaviour first obtained in the case of the Korteweg-deVries equation is also present for other equations.

Moreover, we find that in all cases this behaviour can be encoded in terms of simple symbolic dynamics which are just the dynamics governing a Box & Ball cellular automaton.