Predicate Logic

Abstract

Predicate logic is an extension of the propositional logic to deal with the statements that may apply to many objects. The propositional logic introduced in the preceding chapter allows us to make statements about specific objects, but it does not allow us to make statements applicable to a collection of objects. For example, in the propositional logic we can make the statement: John studies hard, but we cannot make statements like x studies hard, where x is one of the students John, Michael, Steven, or Paul, since the truth value of the statement cannot be determined until x is bound to a specific name. Note that when x is bound to a specific name, the entire statement can be either true or false. For example, the statement John studies hard can be true whereas the statement Steven studies hard can be false.