摘要
Ewa Orlowska presented a class of relations-accessibility relatios determined by a set of parameters. These parameters are a formal counterpart of properties or characteristies of states which are associated by meaas of accessibility relation The author bas showu how properties of sets of parameters influence properties of accessibility relations and give in teresting results. In this paper, some fiurther algebraic properties of relative accessibility are diseussed. We also give a necessary and snfticient condition, under which the set of accessibility relations {R(P)} p包含于PAR forms a lattice by means of usual set operations.
