Nonterminals, Homomorphisms, and Codings in Different Variations of 0L-Systems

Abstract

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 nomomorphisms for all basic types of deterministic OL-languages, including table languages.

Continuing the work begun in Part I of this paper, we consider now variations of nondeterministic OL-systems. The present Part ll of the paper contains a systematic classification of the effect of nonterminals, codings. weak codings, nonerasing homomorphisms and homomorphisms for all basic variations of nondeterministic OL-languages, including table languages.