Two-variable logic has weak, but not strong, Beth definability
Logic
2021-02-03 v3
Abstract
We prove that the two-variable fragment of first-order logic has the weak Beth definability property. This makes the two-variable fragment a natural logic separating the weak and the strong Beth properties since it does not have the strong Beth definability property.
Keywords
Cite
@article{arxiv.2010.00901,
title = {Two-variable logic has weak, but not strong, Beth definability},
author = {H. Andréka and I. Németi},
journal= {arXiv preprint arXiv:2010.00901},
year = {2021}
}