First-order logic is a type of Predicate Logic in which predicates take only individuals as arguments and quantifiers only bind individual variables.
First-order logic is distinguished from propositional logic by its use of quantifiers; each interpretation of first-order logic includes a domain of discourse over which the quantifiers range. Briefly, first-order logic is distinguished from higher-order logics in that quantification is allowed only over atomic entities (individuals but not sets).
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