The partial derivative automaton (Apd) is usually smaller than other non-deterministic finite automata constructed from a regular expression, and it can be seen as a quotient of th...
It is known that the languages definable by formulae of the logics FO2[<,S], 2[<,S], LTL[F,P,X,Y] are exactly the variety DAD. Automata for this class are not known, nor is i...