Strong negation is definable in 2Int

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Authors: Hrafn Valtýr Oddsson
Cited by: 0

Abstract

Abstract In intuitionistic logic, a formula is considered false when absurdity is derivable from it. Nelson’s paraconsistent logic $\text{N4}$ and Wansing’s bi-intuitionistic logic $\text{2Int}$ take two different approaches to introducing a more direct notion of falsity. $\text{N4}$ adds a strong negation connective to the language, which expresses that a formula is refutable, while $\text{2Int}$ formalizes proof and refutation as separate consequence relations, together with separate assumptions and counter-assumptions. This note shows that the strong negation from $\text{N4}$ is definable in $\text{2Int}$.

Fields of Study & Subjects

Computability Logic AI Algorithms Reasoning and Knowledge Advanced Algebra and Logic

Publication details

Journal / source
Journal of Logic and Computation
Volume
36
Issue
6
Publication date
24 June 2026
Language
EN