### Abstract

We consider the use of state elimination to construct shorter regular expressions from finite-state automata. Although state elimination is an intuitive method for computing regular expressions from finite-state automata, the resulting regular expressions are often very long and complicated. We examine the minimization of finite-state automata to obtain shorter expressions first. Then, we introduce vertical chopping based on bridge states and horizontal chopping based on the structural properties of given finite-state automata. We prove that we should not eliminate bridge states until we eliminate all non-bridge states to obtain shorter regular expressions. In addition, we suggest heuristics for state elimination that lead to shorter regular expressions based on vertical chopping and horizontal chopping. Note that we have omitted almost all proofs in this preliminary version.

Original language | English |
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Title of host publication | Implementation and Application of Automata - 10th International Conference, CIAA 2005, Revised Selected Papers |

Pages | 141-152 |

Number of pages | 12 |

Volume | 3845 LNCS |

Publication status | Published - 2006 Jun 23 |

Event | 10th International Conference on Implementation and Application of Automata, CIAA 2005 - Sophia Antipolis, France Duration: 2005 Jun 27 → 2005 Jun 29 |

### Publication series

Name | Lecture Notes in Computer Science (including subseries Lecture Notes in Artificial Intelligence and Lecture Notes in Bioinformatics) |
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Volume | 3845 LNCS |

ISSN (Print) | 0302-9743 |

ISSN (Electronic) | 1611-3349 |

### Other

Other | 10th International Conference on Implementation and Application of Automata, CIAA 2005 |
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Country | France |

City | Sophia Antipolis |

Period | 05/6/27 → 05/6/29 |

### Fingerprint

### All Science Journal Classification (ASJC) codes

- Computer Science(all)
- Biochemistry, Genetics and Molecular Biology(all)
- Theoretical Computer Science

### Cite this

*Implementation and Application of Automata - 10th International Conference, CIAA 2005, Revised Selected Papers*(Vol. 3845 LNCS, pp. 141-152). (Lecture Notes in Computer Science (including subseries Lecture Notes in Artificial Intelligence and Lecture Notes in Bioinformatics); Vol. 3845 LNCS).

}

*Implementation and Application of Automata - 10th International Conference, CIAA 2005, Revised Selected Papers.*vol. 3845 LNCS, Lecture Notes in Computer Science (including subseries Lecture Notes in Artificial Intelligence and Lecture Notes in Bioinformatics), vol. 3845 LNCS, pp. 141-152, 10th International Conference on Implementation and Application of Automata, CIAA 2005, Sophia Antipolis, France, 05/6/27.

**Shorter regular expressions from finite-state automata.** / Han, Yo Sub; Wood, Derick.

Research output: Chapter in Book/Report/Conference proceeding › Conference contribution

TY - GEN

T1 - Shorter regular expressions from finite-state automata

AU - Han, Yo Sub

AU - Wood, Derick

PY - 2006/6/23

Y1 - 2006/6/23

N2 - We consider the use of state elimination to construct shorter regular expressions from finite-state automata. Although state elimination is an intuitive method for computing regular expressions from finite-state automata, the resulting regular expressions are often very long and complicated. We examine the minimization of finite-state automata to obtain shorter expressions first. Then, we introduce vertical chopping based on bridge states and horizontal chopping based on the structural properties of given finite-state automata. We prove that we should not eliminate bridge states until we eliminate all non-bridge states to obtain shorter regular expressions. In addition, we suggest heuristics for state elimination that lead to shorter regular expressions based on vertical chopping and horizontal chopping. Note that we have omitted almost all proofs in this preliminary version.

AB - We consider the use of state elimination to construct shorter regular expressions from finite-state automata. Although state elimination is an intuitive method for computing regular expressions from finite-state automata, the resulting regular expressions are often very long and complicated. We examine the minimization of finite-state automata to obtain shorter expressions first. Then, we introduce vertical chopping based on bridge states and horizontal chopping based on the structural properties of given finite-state automata. We prove that we should not eliminate bridge states until we eliminate all non-bridge states to obtain shorter regular expressions. In addition, we suggest heuristics for state elimination that lead to shorter regular expressions based on vertical chopping and horizontal chopping. Note that we have omitted almost all proofs in this preliminary version.

UR - http://www.scopus.com/inward/record.url?scp=33745121813&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=33745121813&partnerID=8YFLogxK

M3 - Conference contribution

SN - 3540310231

SN - 9783540310235

VL - 3845 LNCS

T3 - Lecture Notes in Computer Science (including subseries Lecture Notes in Artificial Intelligence and Lecture Notes in Bioinformatics)

SP - 141

EP - 152

BT - Implementation and Application of Automata - 10th International Conference, CIAA 2005, Revised Selected Papers

ER -