A pathological o-minimal quotient
Logic
2019-11-26 v2
Abstract
We give an example of a definable quotient in an o-minimal structure which cannot be eliminated over any set of parameters, giving a negative answer to a question of Eleftheriou, Peterzil, and Ramakrishnan. Equivalently, there is an o-minimal structure M whose elementary diagram does not eliminate imaginaries. We also give a positive answer to a related question, showing that any imaginary in an o-minimal structure is interdefinable over an independent set of parameters with a tuple of real elements. This can be interpreted as saying that interpretable sets look "locally" like definable sets, in a sense which can be made precise.
Keywords
Cite
@article{arxiv.1404.3175,
title = {A pathological o-minimal quotient},
author = {Will Johnson},
journal= {arXiv preprint arXiv:1404.3175},
year = {2019}
}
Comments
Withdrawn; incorporated into arXiv:1911.10077