eng
Schloss Dagstuhl – Leibniz-Zentrum für Informatik
Leibniz International Proceedings in Informatics
1868-8969
2021-08-18
79:1
79:18
10.4230/LIPIcs.MFCS.2021.79
article
Idempotent Turing Machines
Nakano, Keisuke
1
https://orcid.org/0000-0003-1955-4225
Research Institute of Electrical Communication, Tohoku University, Sendai, Japan
A function f is said to be idempotent if f(f(x)) = f(x) holds whenever f(x) is defined. This paper presents a computation model for idempotent functions, called an idempotent Turing machine. The computation model is necessarily and sufficiently expressive in the sense that not only does it always compute an idempotent function but also every idempotent computable function can be computed by an idempotent Turing machine. Furthermore, a few typical properties of the computation model such as robustness and universality are shown. Our computation model is expected to be a basis of special-purpose (or domain-specific) programming languages in which only but all idempotent computable functions can be defined.
https://drops.dagstuhl.de/storage/00lipics/lipics-vol202-mfcs2021/LIPIcs.MFCS.2021.79/LIPIcs.MFCS.2021.79.pdf
Turing machines
Idempotent functions
Computable functions
Computation model