On Relative Accessibility Depending on a set of Parameters

Ewa Orlowska^1,2 presented a class of relations-aceessibllity relations determined by a set of parameters. These parameters are a formal counterpart of properties or characteristics of states which are associated by means of accessibility relation. The author has shown how properties of sets of parameters influence properties of accessibility relations and given interesting results. In this paper, some further algebraic properties of relative accessibility are discussed. We also give a necessary and sufficient condition, under which the set of accessibility relations R(P) _P⊆PAR forms a lattice by means of usual set operations.