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.

中文翻译：

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追求本质与偶然性

我们提供用于本质逻辑和事故逻辑以及非偶发性逻辑的Tableaux系统，以显示其对于Kripke语义的正确性和完整性。我们还基于表示这些逻辑的两个非正常运算符的语义不敏感度，显示了这些逻辑之间有趣的相似之处。