The logical equivalence between the material conditional 'if not p then q' and 'p or q' is a foundational theorem of classical propositional logic, representing a basic definition that requires no empirical citation.
The claim states a fundamental, definitional equivalence in classical propositional logic (material implication: thet ¬p → q is equivalent to p ∨ q). By definition, this is common knowledge in logic and mathematics, requiring no external empirical validation or literature citations. Therefore, STEP 0 classifies it as COMMON_KNOWLEDGE.