We prove a new lower bound for the number of distinct languages accepted by binary symmetric difference automata (-NFAs), and compare that to Domaratzki's results (J. Automata Languages Combin. 7(4) (2002) 469) for (traditional) binary nondeterministic finite automata (NFAs). We also show that there are certain regular languages which are accepted by succinct -NFAs, but for which no succinct traditional NFA exists.
