## Barrett, Christopher , and Hunt, Marry, and Marathe, Madhav, and Ravi, S., and Rosenkrantz, Daniel, et al. - Gardens of Eden and Fixed Points in Sequential Dynamical Systems

dmtcs:2294 - Discrete Mathematics & Theoretical Computer Science, January 1, 2001, DMTCS Proceedings vol. AA, Discrete Models: Combinatorics, Computation, and Geometry (DM-CCG 2001)
Gardens of Eden and Fixed Points in Sequential Dynamical Systems

Authors: Barrett, Christopher , and Hunt, Marry, and Marathe, Madhav, and Ravi, S., and Rosenkrantz, Daniel, and Stearns, Richard, and Tosic, Predrag,

A class of finite discrete dynamical systems, called <b>Sequential Dynamical Systems</b> (SDSs), was proposed in [BMR99,BR99] as an abstract model of computer simulations. Here, we address some questions concerning two special types of the SDS configurations, namely Garden of Eden and Fixed Point configurations. A configuration $C$ of an SDS is a Garden of Eden (GE) configuration if it cannot be reached from any configuration. A necessary and sufficient condition for the non-existence of GE configurations in SDSs whose state values are from a finite domain was provided in [MR00]. We show this condition is sufficient but not necessary for SDSs whose state values are drawn from an infinite domain. We also present results that relate the existence of GE configurations to other properties of an SDS. A configuration $C$ of an SDS is a fixed point if the transition out of $C$ is to $C$ itself. The FIXED POINT EXISTENCE (or FPE) problem is to determine whether a given SDS has a fixed point. We show thatthe FPE problem is <b>NP</b>-complete even for some simple classes of SDSs (e.g., SDSs in which each local transition function is from the set{NAND, XNOR}). We also identify several classes of SDSs (e.g., SDSs with linear or monotone local transition functions) for which the FPE problem can be solved efficiently.

Volume: DMTCS Proceedings vol. AA, Discrete Models: Combinatorics, Computation, and Geometry (DM-CCG 2001)
Section: Proceedings
Published on: January 1, 2001
Submitted on: November 21, 2016
Keywords: Computational Complexity,Cellular Automata,Discrete Dynamical Systems,[INFO] Computer Science [cs],[INFO.INFO-CG] Computer Science [cs]/Computational Geometry [cs.CG],[INFO.INFO-DM] Computer Science [cs]/Discrete Mathematics [cs.DM],[MATH.MATH-CO] Mathematics [math]/Combinatorics [math.CO],[INFO.INFO-HC] Computer Science [cs]/Human-Computer Interaction [cs.HC]