The Quotient Operation on Input-Driven Pushdown Automata
Résumé
The quotient of a formal language K by another language L is the set of all strings obtained by taking a string from K that ends with a suffix from L, and removing that suffix. The quotient of a regular language by any language is always regular, whereas the context-free languages and many of their subfamilies, such as the linear and the deterministic languages, are not closed under the quotient operation. This paper establishes the closure of the family of input-driven pushdown automata (IDPDA), also known as visibly pushdown automata, under the quotient operation. A construction of automata representing the result of the operation is given, and its state complexity with respect to nondeterministic IDPDA is shown to be $m^2n + O(m)$, where m and n is the number of states in the automata recognizing K and L, respectively.
Domaines
Informatique [cs]Origine | Fichiers produits par l'(les) auteur(s) |
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