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# exp(+Number, -Result)

Evaluates the exponential function exp(Number) ("e to the power of Number") and unifies the resulting value with Result.

Number
  A number.
Result
  Output: float or breal.

## Description

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

        Result is exp(Number)

which should be preferred for portability.

In coroutining mode, if Number is uninstantiated, the call to exp/2 is delayed until this variable is instantiated.

### Modes and Determinism

- exp(+, -) is det

### Exceptions

(4) instantiation fault
  Number is not instantiated (non-coroutining mode only).
(24) number expected
  Number is not of a numeric type.

## Examples

        Result is exp(0.0).       % gives Result = 1.0
        Result is exp(-6).        % gives Result = 0.00247875

## See Also

is / 2