Structural similarity in context-free languages

Structural Similarity in Context-Free Languages

Divide the context-free languages into equivalence classes in the following way: L1 and L2 are in the same class if there are a-transducers M and M such that M(L1) ~ L~ and d~r(L,) = L1. Define L1 and L~ to be structurally similar if they are in the same class. Among the results given below are: (I) if L1 and L2 are structurally similar and L1 has a structurally similar set of (right) sententia...

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...