English

Mutual Interpretability of Weak Essentially Undecidable Theories

Logic 2021-04-16 v1

Abstract

Kristiansen and Murwanashyaka recently proved that Robinson arithmetic Q is interpretable in an elementary theory of full binary trees, T. We prove that, conversely, T is interpretable in Q by producing a formal interpretation of T in an elementary concatenation theory, thereby also establishing mutual interpretability of T with several well-known weak essentially undecidable theories of numbers, strings and sets. We also in introduce a "hybrid" elementary theory of strings and trees and establish its mutual interpretability with Robinson's weak arithmetic R, the weak theory of binary trees WT of Kristiansen and Murwanashyaka and a weak concatenation theory of Higuchi and Hirohata.

Cite

@article{arxiv.2104.07202,
  title  = {Mutual Interpretability of Weak Essentially Undecidable Theories},
  author = {Zlatan Damnjanovic},
  journal= {arXiv preprint arXiv:2104.07202},
  year   = {2021}
}
R2 v1 2026-06-24T01:11:04.413Z