Individual variable is a basic expression of predicate logic which is used as a place-holder with a predicate letter, instead of an individual constant. In effect, it stands for an unspecified argument of the predicate. Individual variables can be bound by quantifiers, and are indicated by characters of the end of the alphabet.
- Gamut, L.T.F. 1991. Logic, language, and meaning, Univ. of Chicago Press, Chicago.