Probabilistic semantics for Delgrande's conditional logic and a counterexample to his default logic

摘要

This paper establishes two results. First, that a corrected version of the propositional part of Delgrande's conditional logic corresponds to Adams' extended probability logic and has both an infinitesimal and a noninfinitesimal probability semantics. Second, that there is a defect in Delgrande's default logic: it may produce inconsistent extensions.