Acta Informatica

, Volume 4, Issue 1, pp 87–106 | Cite as

Nonterminals, homomorphisms and codings in different variations of OL-systems

I. Deterministic systems
  • M. Nielsen
  • G. Rozenberg
  • A. Salomaa
  • S. Skyum


The use of nonterminals versus the use of homomorphisms of different kinds in the basic types of deterministic OL-systems is studied. A rather surprising result is that in some cases the use of nonterminals produces a comparatively low generative capacity, whereas in some other cases the use of nonterminals gives a very high generative capacity. General results are obtained concerning the use of erasing productions versus the use of erasing homomorphisms. The paper contains a systematic classification of the effect of nonterminals, codings, weak codings, nonerasing homomorphisms and homomorphisms for all basic types of deterministic OL-languages, including table languages.


Information System Operating System Data Structure Communication Network Systematic Classification 
These keywords were added by machine and not by the authors. This process is experimental and the keywords may be updated as the learning algorithm improves.


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Copyright information

© Springer-Verlag 1974

Authors and Affiliations

  • M. Nielsen
    • 2
  • G. Rozenberg
    • 1
  • A. Salomaa
    • 2
  • S. Skyum
    • 2
  1. 1.Mathematics DepartmentUniversity of UtrechtUtrechtThe Netherlands
  2. 2.Computer Science DepartmentUniversity of AarhusAarhusDenmark

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