•  387
    Hyperformalism for Bunched Natural Deduction Systems
    Journal of Philosophical Logic 54 (4): 767-792. 2025.
    Logics closed under classes of substitutions broader than the class of uniform substitutions are known as hyperformal logics. This paper extends known results about hyperformal logics in two ways. First: we examine a very powerful form of hyperformalism that tracks, for bunched natural deduction systems, essentially all the intensional content that can possibly be tracked. We demonstrate that, after a few tweaks, the well-known relevant logic B exhibits this form of hyperformalism. Second: we de…Read more
  •  886
    Logic in the deep end
    Analysis 84 (2): 282-291. 2024.
    Weak enough relevant logics are often closed under depth substitutions. To determine the breadth of logics with this feature, we show there is a largest sublogic of R closed under depth substitutions and that this logic can be recursively axiomatized.
  •  728
    Proof Invariance
    Australasian Journal of Logic 22 (5): 753-772. 2025.
    We explore depth substitution invariance, or hyperformalism, and extend known results in this realm to justification logics extending weak relevant logics. We then examine the surprising invariance of justifications over formulas and restrict our attention to the substitution of proofs in the original relevant logic. The results of this paper indicate that depth invariance is a recalcitrant feature of the logic and that proof structures in hyperformal logics are quite inflexible.