•  24
    Tableaux for essence and contingency
    Logic Journal of the IGPL 29 (5): 719-738. 2021.
    We offer tableaux systems for logics of essence and accident and logics of non-contingency, showing their soundness and completeness for Kripke semantics. We also show an interesting parallel between these logics based on the semantic insensitivity of the two non-normal operators by which these logics are expressed.