Transfers control and passes arguments to a subprogram.  Statement
  format:

     CALL sub[([a][,[a]]...)]

     sub  Is the name of the subroutine subprogram or other
          external procedure, or a dummy argument associated
          with a subroutine subprogram or other external
          procedure.

     a    Is an actual argument optionally preceded by [keyword=],
          where "keyword" is the name of a dummy argument in the
          explicit interface for the subroutine.  The keyword is
          assigned a value when the  procedure is invoked.

  Each actual argument must be a variable, an expression, the name of
  a procedure, or an alternate return specifier.  (It must not be the
  name of an internal procedure, statement function, or the generic
  name of a procedure.)

  An alternate return specifier is an asterisk (*) or ampersand (&)
  followed by the label of an executable branch target statement in
  the same scoping unit as the CALL statement.

                                 NOTE

          An alternate return is an  obsolescent  feature  in
          Fortran  95  and  Fortran 90.  VSI Fortran fully
          supports this feature.

  When the CALL statement is executed, any expressions in the actual
  argument list are evaluated, then control is passed to the first
  executable statement or construct in the subroutine.  When the
  subroutine finishes executing, control returns to the next
  executable statement following the CALL statement, or to a
  statement identified by an alternate return label (if any).

  If an argument list appears, each actual argument is associated
  with the corresponding dummy argument by its position in the
  argument list or by the name of its keyword.  The arguments must
  agree in type and kind type parameters.

  If positional arguments and argument keywords are specified, the
  argument keywords must appear last in the actual argument list.

  If a dummy argument is optional, the actual argument can be
  omitted.

  An actual argument associated with a dummy procedure must be the
  specific name of a procedure, or be another dummy procedure.
  Certain specific intrinsic function names must not be used as
  actual arguments. (See the HP Fortran for OpenVMS Language
  Reference Manual.)

  You can use a CALL statement to invoke a function as long as the
  function is not one of the following types:

   o  REAL(8)

   o  REAL(16)

   o  COMPLEX(8)

   o  COMPLEX(16)

   o  CHARACTER

  EXAMPLES:

  The following example shows a subroutine with argument keywords:

    PROGRAM KEYWORD_EXAMPLE
      INTERFACE
        SUBROUTINE TEST_C(I, L, J, KYWD2, D, F, KYWD1)
        INTEGER I, L(20), J, KYWD1
        REAL, OPTIONAL :: D, F
        COMPLEX KYWD2
        ...
        END SUBROUTINE TEST_C
      END INTERFACE
      INTEGER I, J, K
      INTEGER L(20)
      COMPLEX Z1
      CALL TEST_C(I, L, J, KYWD1 = K, KYWD2 = Z1)
      ...

  The first three actual arguments are associated with their
  corresponding dummy arguments by position.  The argument keywords
  are associated by keyword name, so they can appear in any order.

  Note that the interface to subroutine TEST has two optional
  arguments that have been omitted in the CALL statement.