Safety is not a restriction at level 2 for string languages

Lecture Notes in Computer Science

Volumn 3441, Issue , 2005, Pages 490-504

  Aehlig, K ^a,b   De Miranda, J G ^a   Ong, C H L ^a  

^a UNIVERSITY OF OXFORD   (United Kingdom)

^b UNIVERSITY OF MUNICH   (Germany)

Author keywords

[No Author keywords available]

Indexed keywords

AUTOMATA THEORY; CONTEXT SENSITIVE GRAMMARS; TREES (MATHEMATICS);

PUSHDOWN AUTOMATON; STRING LANGUAGES;

COMPUTER PROGRAMMING LANGUAGES;

EID: 24644508032     PISSN: 03029743     EISSN: None     Source Type: Conference Proceeding    
DOI: 10.1007/978-3-540-31982-5_31     Document Type: Conference Paper

References (13)

1. K. Aehlig, J. G. de Miranda, and C. H. L. Ong. The monadic second order theory of trees given by arbitrary level-two recursion schemes is decidable. TLCA '05 (to appear).
2. K. Aehlig, J. G. de Miranda, and C. H. L. Ong. Safety is not a restriction at level 2 for string languages. Technical Report PRG-RR-04-23, OUCL, 2004.
3. A. Aho. Indexed grammars - an extension of context-free grammars. J. ACM, 15:647-671, 1968.
4. W. Damm. The IO- and OI-hierarchy. TCS, 20:95-207, 1982.
5. W. Damm and A. Goerdt. An automata-theoretical characterization of the OI-hierarchy. Information and Control, 71:1-32, 1986.
6. J. G. de Miranda and G. H. L. Ong. A note on deterministic pushdown languages. Available at http://veb.comlab.ox.ac.uk/oucl/vork/jolie.de.miranda, 2004.
7. T. Knapik, D. Niwiński, and P. Urzyczyn. Deciding monadic theories of hyperalgebraic trees. In TLCA'01, pages 253-267. Springer, 2001. LNCS Vol. 2044.
8. T. Knapik, D. Niwiński, and P. Urzyczyn. Higher-order pushdown trees are easy. In FOSSACS'02pages 205-222. Springer, 2002. LNCS Vol. 2303.
9. T. Knapik, D. Niwiński, P. Urzyczyn, and I. Walukiewicz. Unsafe grammars, panic automata, and decidability. 25 October, 2004.
10. A. N. Maslov. The hierarchy of indexed languages of an arbitrary level. Soviet Math. Dokl., 15:1170-1174, 1974.
11. C. Stirling. Personal email communication. 15 October, 2002.
12. P. Urzyczyn. Personal email communication. 26 July, 2003.
13. M. Y. Vardi. An automata-theoretic approach to linear temporal logic. In Banff Higher Order Workshop, pages 238-266. Springer-Verlag, 1995.