### 8.74 `ERF` — Error function

Description:
  `ERF(X)` computes the error function of X.
Standard:
  Fortran 2008 and later
Class:
  Elemental function
Syntax:
  `RESULT = ERF(X)`
Arguments:

  X | The type shall be `REAL`.

Return value:
  The return value is of type `REAL`, of the same kind as X and lies in the range -1 \leq erf (x) \leq 1 .
Example:

                program test_erf
                  real(8) :: x = 0.17_8
                  x = erf(x)
                end program test_erf

Specific names:

  Name | Argument | Return type | Standard
  `DERF(X)` | `REAL(8) X` | `REAL(8)` | GNU extension