Languages of colonies

AbstractA colony is a finite set of regular grammars, where each grammar generates a finite language. The component grammars cooperate to derive a common language. In this paper we compare the generative power of colonies with two cooperation strategies and with several types of the selection of the alphabet for the common language. The results give representations of languages of colonies in terms of classes of sequential and parallel languages

Descriptional complexity of context-free grammar forms

AbstractDescriptional complexity aspects of grammar forms are studied. It is shown that grammatical complexity measures HEIG, LEVG, VARG, PRODG and DEPG related to any appropriate infinite class G of grammars are unbounded on the infinite class of languages determined by strict/general interpretations of any infinite grammar form