Length considerations in context-free languages

Length Considerations in Context-Free Languages

In this paper we investigate languages containing at most a bounded number of words of each length. We rst show that the context-free languages for which the number of words of every length is bounded by a xed polynomial are exactly the bounded context-free languages in the sense of Ginsburg G]. Thus, we present a length characterization for bounded context-free languages. We then study slender...

Context - Free Languages and

Context-Free Languages, Coalgebraically

We give a coalgebraic account of context-free languages using the functor D(X) = 2 × X for deterministic automata over an alphabet A, in three different but equivalent ways: (i) by viewing context-free grammars as D-coalgebras; (ii) by defining a format for behavioural differential equations (w.r.t. D) for which the unique solutions are precisely the context-free languages; and (iii) as theD-co...

Context-Free Languages

Introduction 1 1 Languages 3 1.1 Notation and examples . . . . . . . . . . . . . . . . . . . . . . . . . 3 1.1.1 Grammars . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3 1.1.2 Examples . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3 1.1.3 Ambiguity . . . . . . . . . . . . . . . . . . . . . . . . . . . 5 1.1.4 Reduced grammars, normal forms . . . . . . . . . . . . . . . 6 1.1...

Parsing of Context Free Languages

Parsing is the process of assigning structure to sentences The structure is obtained from the grammatical description of the language Both in Com puter Science and in Computational Linguistics context free grammars and associated parsing algorithms are among the most useful tools Numerous parsing algorithms have been developed Special subclasses of the context free grammars have been introduced...