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arXiv · 1409.5059

Finite-variable logics do not have weak Beth definability property

H. Andréka·I. Németi
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Abstract

We prove that n-variable logics do not have the weak Beth definability property, for all n greater than 2. This was known for n=3 (Ildik\'o Sain and Andr\'as Simon), and for n greater than 4 (Ian Hodkinson). Neither of the previous proofs works for n=4. In this paper we settle the case of n=4, and we give a uniform, simpler proof for all n greater than 2. The case for n=2 is still open.

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BibTeXRIS

H. Andréka, I. Németi. 2014-09-17. Finite-variable logics do not have weak Beth definability property. https://doi.org/10.1007/978-3-319-15368-1_4

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