graph roles_filtering_stand {
    layout="circo"
    label="roles capability stand"
    fontsize="20"

    r1  [label="r1 provider"];
    r2  [label="r2"];
    r3  [label="r3"];
    r4  [label="r4"];
    r5  [label="r5"];
    r1 -- r2 [headlabel="customer", taillabel="provider"];
    r1 -- r3 [headlabel="peer", taillabel="provider"];
    r1 -- r4 [headlabel="?", taillabel="provider"];
    r1 -- r5 [headlabel="?", taillabel="provider", label="strict-mode"];
}