### Abstract

A subclass of context-free languages, called pure context-free languages, which is generated by context-free grammar with only one type of symbol (i.e., terminals and nonterminals are not distinguished), is introduced and the problem of identifying from positive data a restricted class of monogenic pure context-free languages (mono-PCF languages, in short) is investigated. The class of mono-PCF languages is incomparable to the class of regular languages. In this paper we show that the class of mono-PCF languages is polynomial time identifiable from positive data. That is, there is an algorithm that, given a mono-PCF language L, identifies from positive data, a grammar generating L, called a monogenic pure context-free grammar (mono-PCF grammar, in short) satisfying the property that the time for updating a conjecture is bounded by O (N^{3}), where AT is the sum of lengths of all positive data provided. This is in contrast with another result in this paper that the class of PCF languages is not identifiable in the limit from positive data.

Original language | English |
---|---|

Pages (from-to) | 1503-1510 |

Number of pages | 8 |

Journal | IEICE Transactions on Information and Systems |

Volume | E79-D |

Issue number | 11 |

Publication status | Published - 1996 |

Externally published | Yes |

### Fingerprint

### Keywords

- Inductive inference
- Monogenic pure context-free languages
- Polynomial-time

### ASJC Scopus subject areas

- Information Systems
- Computer Graphics and Computer-Aided Design
- Software

### Cite this

*IEICE Transactions on Information and Systems*,

*E79-D*(11), 1503-1510.

**Inductive inference of monogenic pure context-free languages.** / Tanida, Noriyuki; Yokomori, Takashi.

Research output: Contribution to journal › Article

*IEICE Transactions on Information and Systems*, vol. E79-D, no. 11, pp. 1503-1510.

}

TY - JOUR

T1 - Inductive inference of monogenic pure context-free languages

AU - Tanida, Noriyuki

AU - Yokomori, Takashi

PY - 1996

Y1 - 1996

N2 - A subclass of context-free languages, called pure context-free languages, which is generated by context-free grammar with only one type of symbol (i.e., terminals and nonterminals are not distinguished), is introduced and the problem of identifying from positive data a restricted class of monogenic pure context-free languages (mono-PCF languages, in short) is investigated. The class of mono-PCF languages is incomparable to the class of regular languages. In this paper we show that the class of mono-PCF languages is polynomial time identifiable from positive data. That is, there is an algorithm that, given a mono-PCF language L, identifies from positive data, a grammar generating L, called a monogenic pure context-free grammar (mono-PCF grammar, in short) satisfying the property that the time for updating a conjecture is bounded by O (N3), where AT is the sum of lengths of all positive data provided. This is in contrast with another result in this paper that the class of PCF languages is not identifiable in the limit from positive data.

AB - A subclass of context-free languages, called pure context-free languages, which is generated by context-free grammar with only one type of symbol (i.e., terminals and nonterminals are not distinguished), is introduced and the problem of identifying from positive data a restricted class of monogenic pure context-free languages (mono-PCF languages, in short) is investigated. The class of mono-PCF languages is incomparable to the class of regular languages. In this paper we show that the class of mono-PCF languages is polynomial time identifiable from positive data. That is, there is an algorithm that, given a mono-PCF language L, identifies from positive data, a grammar generating L, called a monogenic pure context-free grammar (mono-PCF grammar, in short) satisfying the property that the time for updating a conjecture is bounded by O (N3), where AT is the sum of lengths of all positive data provided. This is in contrast with another result in this paper that the class of PCF languages is not identifiable in the limit from positive data.

KW - Inductive inference

KW - Monogenic pure context-free languages

KW - Polynomial-time

UR - http://www.scopus.com/inward/record.url?scp=0030291669&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=0030291669&partnerID=8YFLogxK

M3 - Article

VL - E79-D

SP - 1503

EP - 1510

JO - IEICE Transactions on Information and Systems

JF - IEICE Transactions on Information and Systems

SN - 0916-8532

IS - 11

ER -