English

A universal approach to Omitting types for various multimodal and quantifier logics

Logic 2019-12-30 v1

Abstract

We intend to investigate the metalogical property of 'omitting types' for a wide variety of quantifier logics (that can also be seen as multimodal logics upon identifying existential quantifiers with modalities syntactically and semantically) exhibiting the essence of its abstract algebraic facet, namely, atom-canonicity, the last reflecting a well known persistence propery in modal logic. In the spirit of 'universal logic ', with this algebraic abstraction at hand, the omitting types theorem OTT will be studied for various reducts extensions and variants (possibly allowing formulas of infinite length) of first order logic. Our investigatons are algebraic, addressing (non) atom canoicity of varieties of algebra of relations. In the course of our investigations, both negative and positive results will be presented. For example, we show that for any countable theory LnL_n theory TT that has quantifier elimination <2ω< 2^{\omega} many non-principal complete types can be omitted. Furthermore, the maximality (completeness) condition, if eliminated, leads to an independent statement from ZFC\sf ZFC implied by Martin's axiom. OTT\sf OTTs are approached for other algebraizable (in the classical Blok-Pigozzi sense) reformulations or/ and versions of LωωL_{\omega \omega}; they are shown to hold for some and fail for others. We use basic graph theory, finite combinatorics, combinatorial game theory orchestrated by algebraic logic.

Keywords

Cite

@article{arxiv.1912.12114,
  title  = {A universal approach to Omitting types for various multimodal and quantifier logics},
  author = {Tarek Sayed Ahmed},
  journal= {arXiv preprint arXiv:1912.12114},
  year   = {2019}
}

Comments

arXiv admin note: text overlap with arXiv:1608.03513, arXiv:1504.05947, arXiv:1408.3282

R2 v1 2026-06-23T12:57:19.375Z