Availability:Arithmetic function (see is/2)
denominator(+RationalExpr)If RationalExpr evaluates to a rational number or integer,
evaluate to the bottom/right value. Evaluates to 1 (one) if
RationalExpr evaluates to an integer. See also
numerator/1. The
following is true for any rational X.
X =:= numerator(X)/denominator(X).