Classical switching theory has long been held inadequate in the solution of the pragmatic problems that face the logic designer because it is too cumbersome. This is primarily due to the exponential proliferation of states. A theory of sequential switching networks was sought that would yield more convenient methods for the analysis, synthesis, and debugging of switching networks. The basis for such a theory would have to be a departure from the microscopic individual state orientation of classical switching theory towards a macroscopic theory dealing with states and transitions as aggregates.