Back-and-Forth in Space: On Logics and Bisimilarity in Closure Spaces
Vincenzo Ciancia, Diego Latella, Mieke Massink, and Erik de Vink

We adapt the standard notion of bisimilarity for topological models to closure
models and refine it for quasi-discrete closure models. We also define an
additional, weaker notion of bisimilarity that is based on paths in space and
expresses a form of {\em conditional} reachability in a way that is
reminiscent of {\em Stuttering Equivalence} on transition systems. For each
bisimilarity we provide a characterisation with respect to a suitable spatial
logic.