English

Characterizing PSPACE with shallow non-confluent P systems

Computational Complexity 2020-08-05 v1

Abstract

In P systems with active membranes, the question of understanding the power of non-confluence within a polynomial time bound is still an open problem. It is known that, for shallow P systems, that is, with only one level of nesting, non-confluence allows them to solve conjecturally harder problems than confluent P systems, thus reaching PSPACE. Here we show that PSPACE is not only a bound, but actually an exact characterization. Therefore, the power endowed by non-confluence to shallow P systems is equal to the power gained by confluent P systems when non-elementary membrane division and polynomial depth are allowed, thus suggesting a connection between the roles of non-confluence and nesting depth.

Keywords

Cite

@article{arxiv.1902.09523,
  title  = {Characterizing PSPACE with shallow non-confluent P systems},
  author = {Alberto Leporati and Luca Manzoni and Giancarlo Mauri and Antonio E. Porreca and Claudio Zandron},
  journal= {arXiv preprint arXiv:1902.09523},
  year   = {2020}
}

Comments

Preprint. arXiv admin note: text overlap with arXiv:1902.03879

R2 v1 2026-06-23T07:50:38.588Z