English

Connected components in d-minimal structures

Logic 2026-05-13 v3

Abstract

For a given d-minimal expansion R\mathfrak R of the ordered real field, we consider the expansion R\mathfrak R^\natural of R\mathfrak R generated by the sets of the form SCS\bigcup_{S \in \mathcal C}S, where C\mathcal C is a subfamily of the collection of connected components of an R\mathfrak R-definable set. We prove that R\mathfrak R^{\natural} is d-minimal. A similar assertion holds for almost o-minimal expansions of ordered groups.

Keywords

Cite

@article{arxiv.2506.21846,
  title  = {Connected components in d-minimal structures},
  author = {Masato Fujita},
  journal= {arXiv preprint arXiv:2506.21846},
  year   = {2026}
}
R2 v1 2026-07-01T03:35:38.313Z