It is well known that allowing nondeterminism in a finite automaton can produce in the most extreme case an exponential savings in the number of states required to recognize a regular language. This… (More)

The amount of nondeterminism in a nondeterministic finite automaton (NFA) is measured by counting the minimal number of “guessing points” a string w has to pass through on its way to an accepting… (More)

In this paper, we consider two tradeo results regarding the economy of description in parsing. One result is on the tradeo between the size of a parser and its ability to detect an error early. The… (More)

Closures of linear context-free languages under Boolean operations are investigated. The intersection closure and the complementation closure are incomparable. By closing these closures under further… (More)

Meyer and Fischer b][MF] proved that nondeterministic finite automata (NFA) can be exponentially more concise than deterministic finite automata (DFA) in their representations of regular languages.… (More)

The amount of nondeterminism that a pushdown automaton requires to recognize an input string can bemeasured by the minimum number of guesses that it must make to accept the string, where guesses are… (More)

The so-called Chomsky hierarchy [5], consisting of regular, context-free, context-sensitive, and recursively enumerable languages, does not account for many “real world” classes of languages, e.g.,… (More)