Rationals represents the domain of rational numbers, as in x Rationals.
x Rationals evaluates immediately only if x is a numeric quantity.
Simplify[expr Rationals] can be used to try to determine whether an expression corresponds to a rational number.
The domain of integers is taken to be a subset of the domain of rationals.
Rationals is output in TraditionalForm as .
See Section 3.3.10.
See also: Element, Simplify, Algebraics, Integers, Rational, Denominator.
New in Version 4.