digraph lexer {
    rankdir=LR;
    node [shape = doublecircle] LP RP B0 BF DP1 DD0 DD1 DD2 DR0 DR1 INF NAN EXD;
    node [shape = circle];
    BEGIN -> LP  [ label = "(" ];
    BEGIN -> RP  [ label = ")" ];
    BEGIN -> H [ label = "#" ];

    subgraph bools {
        H -> B0 [ label = "t,f" ];
        B0 -> BF [ label = "rue,alse" ];
    }

/*
    subgraph chars {
        H -> SL [ label = "\\" ];
        SL -> CH1 [ label = "*" ];
        SL -> NMCH [ label = "alarm" ];
        SL -> NMCH [ label = "backspace" ];
        SL -> NMCH [ label = "delete" ];
        SL -> NMCH [ label = "escape" ];
        SL -> NMCH [ label = "newline" ];
        SL -> NMCH [ label = "null" ];
        SL -> NMCH [ label = "return" ];
        SL -> NMCH [ label = "space" ];
        SL -> NMCH [ label = "tab" ];
        SL -> XC [ label = "x" ];
    }
*/
     
    subgraph numbers {
        BEGIN -> DD0 [ label = "0-9" ];
        BEGIN -> SN0 [ label = "+,-" ];
        BEGIN -> DP0 [ label = "." ];
        DD0 -> DD0 [ label = "0-9" ];
        DD0 -> DP1 [ label = "." ];
        DP1 -> DD1 [ label = "0-9" ];
        DP0 -> DD1 [ label = "0-9" ];
        DD1 -> DD1 [ label = "0-9" ];
        SN0 -> DD0 [ label = "0-9" ];
        SN0 -> DP0 [ label = "." ];
        SN0 -> INF [ label = "inf.0" ];
        SN0 -> NAN [ label = "nan.0" ];

        H -> NEX [ label = "i,e" ];
        NEX -> DD0 [ label = "0-9" ];
        NEX -> SN0 [ label = "+,-" ];
        NEX -> NXH1 [ label = "#" ];
        NXH1 -> NXD1 [ label = "d" ];
        NXD1 -> DD0 [ label = "0-9" ];
        NXD1 -> SN0 [ label = "+,-" ];
        NXH1 -> NXX1 [ label = "b,o,x" ];
        NXX1 -> SN1 [ label = "+,-" ];
        NXX1 -> DR0 [ label = "Dr" ];

        H -> NBD [ label = "d" ];
        NBD -> DD0 [ label = "0-9" ];
        NBD -> SN0 [ label = "+,-" ];
        NBD -> NBH [ label = "#" ];
        NBH -> NBX [ label = "i,e" ];
        NBX -> SN0 [ label = "+,-" ];
        NBX -> DD0 [ label = "0-9" ];

        H -> NBS [ label = "b,o,x" ];
        NBS -> DR0 [ label = "Dr" ];
        DR0 -> DR0 [ label = "Dr" ];
        NBS -> NXH [ label = "#" ];
        NXH -> NXX [ label = "i,e" ];
        NXX -> DR0 [ label = "Dr" ];

        NBS -> SN1 [ label = "+,-" ];
        NXX -> SN1 [ label = "+,-" ];
        SN1 -> DR0 [ label = "Dr" ];
        SN1 -> INF [ label = "inf.0" ];
        SN1 -> NAN [ label = "nan.0" ];

        DD0 -> EXP [ label = "e" ];
        DP1 -> EXP [ label = "e" ];
        DD1 -> EXP [ label = "e" ];

        EXP -> EXS [ label = "+,-" ];
        EXS -> EXD [ label = "0-9" ];
        EXP -> EXD [ label = "0-9" ];
        EXD -> EXD [ label = "0-9" ];

        DR0 -> FR0 [ label = "/" ];
        FR0 -> DR1 [ label = "Dr" ];
        DR1 -> DR1 [ label = "Dr" ];

        DD0 -> FR1 [ label = "/" ];
        FR1 -> DD2 [ label = "0-9" ];
        DD2 -> DD2 [ label = "0-9" ];
    }
}