Predefined functions can be used to perform text processing operations,
    operate on file specifications and determine the origin of macros. Note
    that, predefined functions can only be used if extended syntax has been
    enabled (use /EXTENDED_SYNTAX qualifier when invoking MMS or, in
    DECwindows MMS, check the Extended Syntax check box in the Build
    Definitions/Directives Options dialog box).

    Where a parameter to a function is considered to be a list of words,
    a word is defined as any sequence of characters, not containing
    white-space characters, that is terminated by a white-space character
    or ')'. White-space characters are space and tab. Functions that
    generate word lists will produce lists that are white-space
    compressed (i.e. no leading or trailing spaces and a single space
    character between each word in the list).