English

Examples of weak amalgamation classes

Logic 2021-07-14 v2

Abstract

We present several examples of hereditary classes of finite structures satisfying the joint embedding property and the weak amalgamation property, but failing the cofinal amalgamation property. These include a continuum-sized family of classes of finite undirected graphs, as well as an example due to Pouzet with countably categorical generic limit.

Keywords

Cite

@article{arxiv.1907.09577,
  title  = {Examples of weak amalgamation classes},
  author = {Adam Krawczyk and Alex Kruckman and Wiesław Kubiś and Aristotelis Panagiotopoulos},
  journal= {arXiv preprint arXiv:1907.09577},
  year   = {2021}
}

Comments

Some additions and tiny corrections; 15 pages

R2 v1 2026-06-23T10:27:40.953Z