FLOOR (real-number [,KIND])

  Class:  Elemental function - Generic

  Returns the greatest integer less than or equal to its argument.

  The result is of type default integer (unless KIND specifies a
  different integer KIND).  The result value is equal to the greatest
  integer less than or equal to the argument.  The result is
  undefined if the value cannot be represented in the default integer
  range.

  Examples:

  FLOOR (4.8) has the value 4.

  FLOOR (-5.6) has the value -6.