EXP (exponent)

  Class:  Elemental function - Generic

  Returns e**X, where X is the value of the argument.

  +------+---------+----------+------------+-------------+
  | Args | Generic | Specific |  Argument  | Result Type |
  +------+---------+----------+------------+-------------+
  |  1   |  EXP    | EXP      | REAL*4     | REAL*4      |
  |      |         | DEXP     | REAL*8     | REAL*8      |
  |      |         | QEXP     | REAL*16    | REAL*16     |
  |      |see note | CEXP     | COMPLEX*8  | COMPLEX*8   |
  |      |         | CDEXP    | COMPLEX*16 | COMPLEX*16  |
  |      |         | ZEXP     | COMPLEX*16 | COMPLEX*16  |
  |      |         | CQEXP    | COMPLEX*32 | COMPLEX*32  |
  +------+---------+----------+------------+-------------+

  Note: The setting of compiler options specifying real
        size can affect CEXP.