@ ARGUMENTS

        [SIC\]@ Macro_Name [Arg1 [Arg2 [...]]]

    The arguments passed to the macro are described by the structure PRO%:
        - PRO%NAME: calling procedure name,
        - PRO%NARG: number of arguments passed,
        - PRO%ARG: a character array (size PRO%NARG) providing all the
          arguments. This array is not defined if PRO%NARG is 0.
    The structure is updated when entering each macro. Up to  32  parameters
    can be given.

    Note  that  the  arguments are all saved as character strings. A typical
    use is:
        SIC> LET MYVAR 'PRO%ARG[1]'
    to substitute the character string by its content. See also  HELP  PARSE
    for advanced argument parsing.

    The old-fashion way to access the arguments is to use the tokens &1, &2,
    ..., &9. They are substituted to the corresponding arguments as they are
    found  in  the body of the procedure, even within character strings. For
    example
        SIC> say "a&1b"
    will display the first argument value surrounded by "a"  and  "b".  Note
    that these tokens can be used to access the 9 first arguments only.