Unlike first-order logic, propositional logic does not deal with non-logical objects, predicates about them, or quantifiers. However, all the machinery of propositional logic is included in first-order logic and higher-order logics. In this sense, propositional logic is the foundation of first-order logic and higher-order logic.
unlike first-order logic propositional logic does not deal with non-logical objects predicates about them or quantifiers however all the machinery of propositional logic is included in first-order logic and higher-order logics in this sense propositional logic is the foundation of first-order logic and higher-order logic