@INPROCEEDINGS{Bor_j2000, author = "Henning~Bordihn", title = "On the number of active symbols in {L} and {CD} grammar systems", booktitle = "Theorietag 2000 mit Workshop New Computing Paradigms: Molecular Computing and Quantum Computing (Wien, {\"O}sterreich)", publisher = "Technische Universit{\"a}t Wien, Institut f{\"u}r Computersprachen", year = 2000, editor = "Rudolf~Freund", pages = "175--176" }