### Abstract

Motivated by aspects of robustness in parsing a context-free language, we study generalized fuzzy context-free grammars. These fuzzy context-free $K$-grammars provide a general framework to describe correctly as well as erroneously derived sentences by a single generating mechanism. They model the situation of making a finite choice out of an infinity of possible grammatical errors during each context-free derivation step. Formally, a fuzzy context-free $K$-grammar is a fuzzy context-free grammar with a countable rather than a finite number of rules satisfying the following condition: for each symbol $\alpha$, the set containing all right-hand sides of rules with left-hand side equal to $\alpha$ forms a fuzzy language that belongs to a given family $K$ of fuzzy languages. We investigate the generating power of fuzzy context-free $K$-grammars, and we show that under minor assumptions on the parameter $K$, the family of languages generated by fuzzy context-free $K$-grammars possesses closure properties very similar to those of the family of ordinary context-free languages.

Original language | Undefined |
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Pages (from-to) | 167-190 |

Number of pages | 24 |

Journal | Theoretical computer science |

Volume | 347 |

Issue number | 1-2 |

DOIs | |

Publication status | Published - 2005 |

### Keywords

- MSC-68Q45
- EWI-2712
- HMI-SLT: Speech and Language Technology
- MSC-68Q42
- METIS-227288
- MSC-03E72
- IR-53904

## Cite this

Asveld, P. R. J. (2005). Fuzzy context-free languages - Part 1: Generalized fuzzy context-free grammars.

*Theoretical computer science*,*347*(1-2), 167-190. https://doi.org/10.1016/j.tcs.2005.06.012