Table 6 State transition table for restricted DOS pathname

  State  Substate  Target  True   False    Action    BadFcn
-------------------------------------------------------------
    A       0        a       1     ERR     pushcar   errmsg
    B       1       ':'      2     ERR    savedrive  errmsg
    C       2        \       3     ERR   appendpath  errmsg
    D       3        a       4     ERR     pushcar   errmsg
    E       4        \       3      5    appendpath   skip
            5        x       4      6      pushcar    skip
            6       '.'      8      7     savefname   skip
            7        e      13    ERR    savefname   errmsg
    F       8        x       9     ERR     pushchar  errmsg
    G       9        x      11    10      pushchar    skip
            10       e      13    ERR      saveext   errmsg
    H       11       x      12    12      pushchar    skip
            12       e      13    ERR     saveext    errmsg
    I       13       e     OUT   ERR      cleanup    errmsg