English

Small weakly universal Turing machines

Computational Complexity 2007-08-01 v1

Abstract

We give small universal Turing machines with state-symbol pairs of (6, 2), (3, 3) and (2, 4). These machines are weakly universal, which means that they have an infinitely repeated word to the left of their input and another to the right. They simulate Rule 110 and are currently the smallest known weakly universal Turing machines.

Cite

@article{arxiv.0707.4489,
  title  = {Small weakly universal Turing machines},
  author = {Turlough Neary and Damien Woods},
  journal= {arXiv preprint arXiv:0707.4489},
  year   = {2007}
}
R2 v1 2026-06-21T09:03:11.219Z