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individual variable
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individual variable

logic
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An individual variable in logic is a placeholder that can be replaced by a specific name or description of an individual. This concept is fundamental to the predicate calculus, a system used to represent propositions involving properties and relations.123

In this system, individual variables, often denoted by letters like x, y, or z, are combined with predicates (which represent properties or relations) to form atomic formulas. For example, if 'P' represents the predicate "is wise" and 'x' is an individual variable, then 'Px' can represent "x is wise". Quantifiers, such as the universal quantifier (\u2200) meaning "for all" and the existential quantifier (\u2203) meaning "for some," are used with these variables to create more complex logical statements. For instance, (\u2200x)\u03d5x means "for all x, x has property \u03d5".234

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5 Britannica Sources
  1. philosophy of logic - Nature and varieties of logic
  2. formal logic - Definite descriptions
  3. formal logic - Validity in modal logic
  4. individual variable
  5. predicate variable

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