[ Arithmetic | The ECLiPSe Built-In Predicates | Reference Manual | Alphabetic Index ]
# denominator(+Number, -Result)

Extracts the denominator of the rational Number and unifies the resulting
integer with Result.
*Number*
- An integer or rational number.
*Result*
- A variable or integer.

## Description

This predicate is used by the ECLiPSe compiler to expand evaluable
arithmetic expressions. So the call to denominator(Number, Result) is
equivalent to
Result is denominator(Number)

which should be preferred.
In coroutining mode, if Number is uninstantiated, the call to
denominator/2 is delayed until this variable is instantiated.

### Modes and Determinism

### Exceptions

*(4) instantiation fault *
- Number is not instantiated (non-coroutining mode only).
*(5) type error *
- Number is a float or breal.
*(5) type error *
- Result is a number but not an integer.
*(24) number expected *
- Number is not of a numeric type.
*(24) number expected *
- Result is neither a number nor a variable.

## Examples

Success:
denominator(3_4, 4).
denominator(9_12, 4).
denominator(-3_4, 4).
denominator(25, 1).
Fail:
denominator(3_4, 3).
Error:
denominator(A, 3). (Error 4).
denominator(3.1, 3). (Error 5).
denominator(3_4, 3_1). (Error 5).
denominator(3_4, r). (Error 24).
denominator(1_3 + 3_4, 12). (Error 24).

## See Also

is / 2, numerator / 2, rational / 2