digraph G{
        d2tdocpreamble = "\usetikzlibrary{automata}";
        d2tfigpreamble = "\tikzstyle{every state}= \
        [draw=blue!50,very thick,shape=circle, fill=blue!20]";
        node [style="state"];
        edge [lblstyle="fill=blue!20", style="arrows=->", topath="bend left"];
        s1 [style="state, initial"]
        s0 [style="state, accepting"]
        s1 -> s3 [texlbl="A"]
        s1 -> s0 [texlbl="C"]
        s1 -> s2 [texlbl="B"]
        s2 -> s3 [texlbl="A"]
        s2 -> s0 [texlbl="C"]
        s2 -> s2 [texlbl="B"]
        s3 -> s3 [texlbl="A"]
        s3 -> s0 [texlbl="C"]
        s3 -> s2 [texlbl="B"]
}