Tree-Like Justification Systems are Consistent

Justification theory [3] is a unifying theory to capture semantics of non-monotonic logics. Largely thanks to its abstract nature, it is a powerful framework with many use cases. First, it provides a mechanism to define new logics based on well-known principles in a uniform way, as well as to transfer results between domains. Second, it brings order in the zoo of logics and semantics, by enabling a systematic comparison between multiple semantics for a single logic and between different logics, for instance by answering the question whether a certain semantics of a given logic coincides with a semantics of another logic.