NEAREST (real-number-a, real-number-b)

  Class:  Elemental function - Generic

  Returns the nearest different number (representable on the
  processor) in a given direction.

  The result type is the same as "real-number-a"; a positive
  "real-number-b" returns the nearest number in the direction of
  positive infinity. A negative one goes in the direction of
  negative infinity.

  Example:

  If 3.0 and 2.0 are REAL*4 values, NEAREST (3.0, 2.0) has the
  value 3 + 2**-22, which equals approximately 3.0000002, while
  NEAREST (3.0, -2.0) has the value 3-2**-22, which approximately
  equals 2.9999998.  For more information on the REAL*4 model,
  see the HP Fortran for OpenVMS Language Reference Manual.