Lower Bound of the Number of Threshold Functions

For reduced finite Moore automata corresponding to regular expressions which are finite sums of expressions of the form E+HΣ*G (E,H,G are finite events and Σis the set of inputs) it is shown that an arbitrary change of the initial state or of the set of final states results in an automaton belonging to the same class. The transition graphs corresponding to the single inputs in definite and reverse-definite automata are investigated.