Stephen Read presented harmonious inference rules for identity in classical predicate logic. I demonstrate here how this approach can be generalised to a setting where predicate logic has been extended with epistemic modals. In such a setting, identity has two uses. A rigid one, where the identity of two referents is preserved under epistemic possibility, and a non-rigid one where two identical referents may differ under epistemic modality. I give rules for both uses. Formally, I extend Quantified Epistemic Multilateral Logic with two identity signs. I argue that a uniform meaning for identity tout court can be given by adopting Maria Aloni’s account of reference using conceptual covers. We obtain a harmonious set of rules for identity that is sound and complete for Aloni’s model theory.

Stephen Read 提出了经典谓词逻辑中同一性的和谐推理规则。我在这里演示如何将这种方法推广到谓词逻辑已使用认知模态扩展的设置。在这种情况下，身份有两个用途。一种是刚性的，其中两个指称的身份在认知可能性下得到保留，另一种是非刚性的，其中两个相同的指称可能在认知模态下不同。我给出了两种用途的规则。形式上，我用两个恒等符号扩展了量化认知多边逻辑。我认为，通过采用 Maria Aloni 的使用概念封面的参考说明，可以给出身份的统一含义。我们获得了一套和谐的恒等式规则，这对于 Aloni 的模型理论来说是健全和完整的。