@article {,
	title = {Trading polarizations for labels in P systems with active membranes },
	journal = {Acta Informatica},
	volume = {41},
	year = {2004},
	pages = {111-144},
	publisher = {Springer Verlag},
	address = {Amsterdam, Netherlands},
	abstract = {This paper addresses the problem of removing the polarization of membranes from P systems with active membranes - and this is achieved by allowing the change of membrane labels by means of communication rules or by membrane dividing rules. As consequences of these results, we obtain the universality of P systems with active membranes which are allowed to change the labels of membranes, but do not use polarizations. Universality results are easily obtained also by direct proofs. By direct constructions, we also prove that <Emphasis FontCategory="NonProportional">SAT</Emphasis> can be solved in linear time by systems without polarizations and with label changing possibilities. If non-elementary membranes can be divided, then <Emphasis FontCategory="NonProportional">SAT</Emphasis> can be solved in linear time without using polarizations and label changing. Several open problems are also formulated. 
},
	issn = {0001-5903},
	doi = {10.1007/s00236-004-0153-z},
	url = {http://www.springerlink.com/index/A7HGMKPDA0W7F0W2.pdf},
	attachments = {http://www.gcn.us.es/biblio/sites/all/modules/lightbox2/files/Trading polarizations for Labels....pdf},
	author = {Artiom Alhazov and Linqiang Pan and Gheorghe Paun}
}
