Cellular automata can really solve the parity problem

Fuente: arXiv
Saved in:
Bibliographic Details
Main Authors: Wolnik, Barbara, Nenca, Anna, Balbi, Pedro Paulo, De Baets, Bernard
Format: Preprint
Published: 2025
Subjects:
Online Access:
Tags: Add Tag
No Tags, Be the first to tag this record!
_version_ 1866915607809622016
author Wolnik, Barbara
Nenca, Anna
Balbi, Pedro Paulo
De Baets, Bernard
author_facet Wolnik, Barbara
Nenca, Anna
Balbi, Pedro Paulo
De Baets, Bernard
contents Determining properties of an arbitrary binary sequence is a challenging task if only local processing is allowed. Among these properties, the determination of the parity of 1s by distributed consensus has been a recurring endeavour in the context of automata networks. In its most standard formulation, a one-dimensional cellular automaton rule should process any odd-sized cyclic configuration and lead the lattice to converge to the homogeneous fixed point of 0s if the parity of 1s is even and to the homogeneous fixed point of 1s, otherwise. The only known solution to this problem with a single rule was given by Betel, de Oliveira and Flocchini (coined BFO rule after the authors' initials). However, three years later the authors of the BFO rule realised that the rule would fail for some specific configuration and proposed a computationally sound fix, but a proof could not be worked out. Here we provide another fix to the BFO rule along with a full proof, therefore reassuring that a single-rule solution to the problem really does exist.
format Preprint
id arxiv_https___arxiv_org_abs_2501_08684
institution arXiv
publishDate 2025
record_format arxiv
spellingShingle Cellular automata can really solve the parity problem
Wolnik, Barbara
Nenca, Anna
Balbi, Pedro Paulo
De Baets, Bernard
Dynamical Systems
Formal Languages and Automata Theory
Determining properties of an arbitrary binary sequence is a challenging task if only local processing is allowed. Among these properties, the determination of the parity of 1s by distributed consensus has been a recurring endeavour in the context of automata networks. In its most standard formulation, a one-dimensional cellular automaton rule should process any odd-sized cyclic configuration and lead the lattice to converge to the homogeneous fixed point of 0s if the parity of 1s is even and to the homogeneous fixed point of 1s, otherwise. The only known solution to this problem with a single rule was given by Betel, de Oliveira and Flocchini (coined BFO rule after the authors' initials). However, three years later the authors of the BFO rule realised that the rule would fail for some specific configuration and proposed a computationally sound fix, but a proof could not be worked out. Here we provide another fix to the BFO rule along with a full proof, therefore reassuring that a single-rule solution to the problem really does exist.
title Cellular automata can really solve the parity problem
topic Dynamical Systems
Formal Languages and Automata Theory
url https://arxiv.org/abs/2501.08684