2016-02-112016-02-11200484-688-6101-4http://hdl.handle.net/11441/34559In P systems with gemmation of mobile membranes were ex- amined. It was shown that (extended) systems with eight membranes are as powerful as the Turing machines. Moreover, it was also proved that extended gemmating P systems with only pre-dynamical rules are still computationally complete: in this case nine membranes are needed to obtain this computational power. In this paper we improve the above results concerning the size bound of extended gemmating P systems, namely we prove that these systems with at most ¯ve membranes (with meta-priority relations and without (in=out) communication rules) form a class of universal computing devices, while in the case of extended systems with only pre-dynamical rules six membranes are enough to determine any recursively enumerable language.application/pdfengAttribution-NonCommercial-NoDerivatives 4.0 Internacionalhttp://creativecommons.org/licenses/by-nc-nd/4.0/info:eu-repo/semantics/conferenceObjectinfo:eu-repo/semantics/openAccess