Title: Epistemic Modeling with Justifications,
Abstract: Existing logical models do not fairly represent epistemic situations with
fallible justifications, e.g., Russell's Prime Minister example, though such
scenarios have long been at the center of epistemic studies. We introduce
justification epistemic models, JEM, which can handle such scenarios. JEM makes
justifications prime objects and draws a distinction between accepted and
knowledge-producing justifications; belief and knowledge become derived
notions. Furthermore, Kripke models can be viewed as special cases of JEMs with
additional assumptions of evidence insensitivity and common knowledge of the
model. We argue that JEM can be applied to a range of epistemic scenarios in
CS, AI, Game Theory, etc.