argument-list
    OpenVMS usage:arg_list
    type:         unspecified
    access:       read only
    mechanism:    by reference, array reference
    Argument list to be passed to user-procedure. The argument-
    list argument is the address of an array of quadwords that is
    the argument list. The first quadword contains the count of the
    remaining quadwords, to a maximum of 255.
 user-procedure
    OpenVMS usage:procedure
    type:         procedure value
    access:       function call (before return)
    mechanism:    by value
    Routine that LIB$CALLG_64 calls with the specified argument list.