Open Ended Systems, Dynamic Bisimulation and Tile Logic

The sos formats ensuring that bisimilarity is a congruence often fail in the presence of structural axioms on the algebra of states. Dynamic bisimulation, introduced to characterize the coarsest congruence for ccs which is also a (weak) bisimulation, reconciles the bisimilarity as congruence property with such axioms and with the specification of open ended systems, where states can be reconfigured at run-time, at the cost of an infinitary operation at the meta-level. We show that the compositional framework offered by tile logic is suitable to deal with structural axioms and open ended systems specifications, allowing for a finitary presentation of context closure.