Open AccessMACROS, Iterated Substitution and Lindenmayer AFLs
Author(s) -
Arto Salomaa
Publication year - 1973
Publication title -
daimi pb
Language(s) - English
Resource type - Journals
eISSN - 2245-9316
pISSN - 0105-8517
DOI - 10.7146/dpb.v2i18.6437
Subject(s) - substitution (logic) , iterated function , closure (psychology) , context (archaeology) , macro , grammar , rule based machine translation , computer science , mathematics , scheme (mathematics) , algebra over a field , discrete mathematics , pure mathematics , programming language , natural language processing , linguistics , mathematical analysis , paleontology , philosophy , economics , market economy , biology
The notion of a K-iteration grammar, where K is a family of languages, provides a uniform framework for discussing the various language families obtained by context-free Lindenmayer systems. It is shown that the family of languages generated by K-iteration grammars possesses strong closure properties under the assumption that K itself has certain weak closure properties. Along these lines, the notion of a hyper-AFL is introduced and some open problems are posed.