Alternative space definitions for P systems with active membranes

Abstract The first definition of space complexity for P systems was based on a hypothetical real implementation by means biochemical materials, and thus it assumes that every single object or membrane requires some constant physical space. This is equivalent to using unary encoding represent multiplicities each membrane. A different approach can also be considered, having in mind an silico; this case, the multiplicity stored binary numbers, reducing amount needed In paper, we give formal alternative measure, define corresponding classes compare such both with standard defined framework considering original