digraph block {
    N0[label="entry"];
    N1[label="exit"];
    N2[label="expr 1is"];
    N3[label="expr 7is"];
    N4[label="expr 17is"];
    N5[label="expr [1is, 7is, 17is]"];
    N6[label="local _v"];
    N7[label="stmt let _v = [1is, 7is, 17is];"];
    N8[label="block { let _v = [1is, 7is, 17is]; }"];
    N0 -> N2;
    N2 -> N3;
    N3 -> N4;
    N4 -> N5;
    N5 -> N6;
    N6 -> N7;
    N7 -> N8;
    N8 -> N1;
}