Some Remarks on Real-Time Turing Machines
Computational Complexity
2019-02-05 v1
Abstract
The power of real-time Turing machines using sublinear space is investigated. In contrast to a claim appearing in the literature, such machines can accept non-regular languages, even if working in deterministic mode. While maintaining a standard binary counter appears to be impossible in real-time, we present a guess and check approach that yields a binary representation of the input length. Based on this technique, we show that unary encodings of languages accepted in exponential time can be recognized by nondeterministic real-time Turing machines.
Cite
@article{arxiv.1902.00975,
title = {Some Remarks on Real-Time Turing Machines},
author = {Holger Petersen},
journal= {arXiv preprint arXiv:1902.00975},
year = {2019}
}