Multi-Head Finite Automata: Characterizations, Concepts and Open Problems
Abstract
Multi-head finite automata were introduced in (Rabin, 1964) and (Rosenberg, 1966). Since that time, a vast literature on computational and descriptional complexity issues on multi-head finite automata documenting the importance of these devices has been developed. Although multi-head finite automata are a simple concept, their computational behavior can be already very complex and leads to undecidable or even non-semi-decidable problems on these devices such as, for example, emptiness, finiteness, universality, equivalence, etc. These strong negative results trigger the study of subclasses and alternative characterizations of multi-head finite automata for a better understanding of the nature of non-recursive trade-offs and, thus, the borderline between decidable and undecidable problems. In the present paper, we tour a fragment of this literature.
- Publication:
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arXiv e-prints
- Pub Date:
- June 2009
- DOI:
- 10.48550/arXiv.0906.3051
- arXiv:
- arXiv:0906.3051
- Bibcode:
- 2009arXiv0906.3051H
- Keywords:
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- Computer Science - Computational Complexity;
- Computer Science - Formal Languages and Automata Theory
- E-Print:
- EPTCS 1, 2009, pp. 93-107