Split Interpolation: Refining Craig's Theorem via Three-Valued Logics
Abstract
Which choices of truth tables and consequence relations for two logics and ensure the satisfaction of the following split interpolation property: If two formulas and share at least one propositional atom and classically entails , then there is a formula that shares all its propositional atoms with both and , such that entails in and entails in ? We identify the cases in which this property holds for any pair of propositional logics based on the same three-valued Boolean normal monotonic scheme for connectives and two monotonic consequence relations. Since the resulting logics are subclassical, every instance of this property constitutes a particular refinement of Craig's deductive interpolation theorem, as it entails the latter and further restricts the range of possible interpolants.
Keywords
Cite
@article{arxiv.2503.20924,
title = {Split Interpolation: Refining Craig's Theorem via Three-Valued Logics},
author = {Quentin Blomet},
journal= {arXiv preprint arXiv:2503.20924},
year = {2025}
}