Output-extended sequential machines

A new class of sequential machine, called output-extended, is defined. In contradistinction to Moore and Mealy machines, the output state here is a function of the previous output as well as the present state and input. A particular form of output-extended machine is studied, in which the function in question is the Boolean intersection of the present output in the Mealy sense and the previous output. It is shown that this structure offers possibilities of state reduction not present in the orginal Mealy machine.