edges.gv
digraph G {
label="edge config";
A->Box [label="edge label", arrowhead=box];
Box->Crow[arrowhead=crow];
Crow->Dot[arrowhead=dot];
B->Inv[arrowhead=inv];
Inv->Tee[arrowhead=tee];
Tee->Normal[arrowhead=normal, headlabel="Normal"];
a->Diamond [ arrowhead=diamond];
Diamond->OpenDiamond [arrowhead=odiamond];
OpenDiamond->LDiamond [arrowhead=ldiamond];
}