A synonym for Integer. The word ``rational'' is sometimes used for emphasis to distinguish it from other types of ``integers'' such as Cyclotomic Integers, Eisenstein Integers, and Gaussian Integers.
See also Cyclotomic Integer, Eisenstein Integer, Gaussian Integer, Integer, Rational Number
References
Hardy, G. H. and Wright, E. M. An Introduction to the Theory of Numbers, 5th ed.
Oxford, England: Clarendon Press, p. 1, 1979.