@article {757, title = {Towards bridging two cell-inspired models: P systems and R systems}, journal = {Ninth Brainstorming Week on Membrane Computing}, year = {2011}, month = {02/2011}, pages = {305-316}, publisher = {F{\'e}nix Editora}, address = {Seville, Spain}, abstract = {We examine, from the point of view of membrane computing, the two basic assumptions of reaction systems, the \threshold" and \no permanence" ones. In certain circumstances (e.g., de{\textasciimacron}ning the successful computations by local halting), the second assumption can be incorporated in a transition P system or in a symport/antiport P system without losing the universality. The case of the {\textasciimacron}rst postulate remains open: the reaction systems deal, deterministically, with {\textasciimacron}nite sets of symbols, which is not of much interest for computing; three ways to introduce nondeterminism are suggested and left as research topics.}, url = {http://www.gcn.us.es/9bwmc_proceedings}, author = {Gheorghe Paun and Mario J. P{\'e}rez-Jim{\'e}nez} }