1 Department of Computer Science, Faculty of Science, Aarhus University, Aarhus University2 Department of Computer Science, Science and Technology, Aarhus University3 Department of Computer Science, Science and Technology, Aarhus University
The use of nonterminals versus the use of codings in variations of OL-systems is studied. It is shown that the use of nonterminals produces a comparatively low generative capacity in deterministic systems while it produces a comparatively high generative capacity in nondeterministic systems. Finally it is proved that the family of context-free languages is contained in the family generated by codings on propagating OL-systems with a finite set of axioms, which was one of the open problems in . All the results in this paper can be found in  and .
Lecture Notes in Computer Science, 1974, p. 244-249