English

Adding linear orders

Logic 2012-08-14 v1

Abstract

We address the following question: Can we expand an NIP theory by adding a linear order such that the expansion is still NIP? Easily, if acl(A)=A for all A, then this is true. Otherwise, we give counterexamples. More precisely, there is a totally categorical theory for which every expansion by a linear order has IP. There is also an \omega-stable NDOP theory for which every expansion by a linear order interprets bounded arithmetic.

Keywords

Cite

@article{arxiv.1103.0206,
  title  = {Adding linear orders},
  author = {Saharon Shelah and Pierre Simon},
  journal= {arXiv preprint arXiv:1103.0206},
  year   = {2012}
}
R2 v1 2026-06-21T17:33:40.370Z