English

Reasoning about proof and knowledge

Logic in Computer Science 2019-01-01 v4

Abstract

In previous work [Lewitzka, Log. J. IGPL 2017], we presented a hierarchy of classical modal systems, along with algebraic semantics, for the reasoning about intuitionistic truth, belief and knowledge. Deviating from G\"odel's interpretation of IPC in S4, our modal systems contain IPC in the way established in [Lewitzka, J. Log. Comp. 2015]. The modal operator can be viewed as a predicate for intuitionistic truth, i.e. proof. Epistemic principles are partially adopted from Intuitionistic Epistemic Logic IEL [Artemov and Protopopescu, Rev. Symb. Log. 2016]. In the present paper, we show that the S5-style systems of our hierarchy correspond to an extended Brouwer-Heyting-Kolmogorov interpretation and are complete w.r.t. a relational semantics based on intuitionistic general frames. In this sense, our S5-style logics are adequate and complete systems for the reasoning about proof combined with belief or knowledge. The proposed relational semantics is a uniform framework in which also IEL can be modeled. Verification-based intuitionistic knowledge formalized in IEL turns out to be a special case of the kind of knowledge described by our S5-style systems.

Keywords

Cite

@article{arxiv.1709.06672,
  title  = {Reasoning about proof and knowledge},
  author = {Steffen Lewitzka},
  journal= {arXiv preprint arXiv:1709.06672},
  year   = {2019}
}

Comments

51 pages. The final corrected version is published in Annals of Pure and Applied Logic (2018), https://doi.org/10.1016/j.apal.2018.10.001