On computational complexity of counting fixed points in symmetric boolean graph automata

Predrag T. Tošić, Gui A. Agha

Research output: Contribution to journalConference articlepeer-review


We study computational complexity of counting the fixed point configurations (FPs) in certain classes of graph automata viewed as discrete dynamical systems. We prove that both exact and approximate counting of FPs in Sequential and Synchronous Dynamical Systems (SDSs and SyDSs, respectively) are computationally intractable, even when each node is required to update according to a symmetric Boolean function. We also show that the problems of counting exactly the garden of Eden configurations (GEs), as well as all transient configurations, are in general intractable, as well. Moreover, exactly enumerating FPs or GEs remains hard even in some severely restricted cases, such as when the nodes of an SDS or SyDS use only two different symmetric Boolean update rules, and every node has a neighborhood size bounded by a small constant.

Original languageEnglish (US)
Pages (from-to)191-205
Number of pages15
JournalLecture Notes in Computer Science
StatePublished - Oct 31 2005
Event4th International Conference on Unconventional Computation, UC 2005 - Sevilla, Spain
Duration: Oct 3 2005Oct 7 2005


  • #P-completeness
  • Cellular and graph automata
  • Computational complexity
  • Configuration space properties
  • Sequential and synchronous dynamical systems

ASJC Scopus subject areas

  • Theoretical Computer Science
  • Computer Science(all)


Dive into the research topics of 'On computational complexity of counting fixed points in symmetric boolean graph automata'. Together they form a unique fingerprint.

Cite this