1digraph G {
2  // leave some space for the head/taillabels
3  graph [ranksep=1.5 splines=true overlap=false]
4
5  // to avoid confusion, remember this:
6  // it's spelt tail/head, but it's read start/end
7
8  // emphasize theatrically
9//  edge [arrowsize=2]
10  // put head/tail labels farther from the node
11  edge [labeldistance=3]
12
13  // not interested in node labels
14  node [shape=circle width=0.5 label=""]
15
16  {
17    edge [dir=back samehead=ahead]
18    a->Z [arrowtail=none taillabel=none]
19    b->Z [arrowtail=normal taillabel=normal]
20    c->Z [arrowtail=inv taillabel=inv]
21    d->Z [arrowtail=dot taillabel=dot]
22    e->Z [arrowtail=odot taillabel=odot]
23    f->Z [arrowtail=invdot taillabel=invdot]
24    g->Z [arrowtail=invodot taillabel=invodot]
25    h->Z [arrowtail=open taillabel=open]
26    i->Z [arrowtail=halfopen taillabel=halfopen arrowhead=inv headlabel=samehead]
27    j->Z [arrowtail=empty taillabel=empty]
28    k->Z [arrowtail=invempty taillabel=invempty]
29    l->Z [arrowtail=diamond taillabel=diamond]
30    m->Z [arrowtail=odiamond taillabel=odiamond]
31    n->Z [arrowtail=box taillabel=box]
32    o->Z [arrowtail=obox taillabel=obox]
33    p->Z [arrowtail=tee taillabel=tee]
34    q->Z [arrowtail=crow taillabel=crow]
35  }
36  {
37    edge [dir=forward sametail=atail]
38    Z->A [arrowhead=none headlabel=none]
39    Z->B [arrowhead=normal headlabel=normal]
40    Z->C [arrowhead=inv headlabel=inv]
41    Z->D [arrowhead=dot headlabel=dot]
42    Z->E [arrowhead=odot headlabel=odot]
43    Z->F [arrowhead=invdot headlabel=invdot]
44    Z->G [arrowhead=invodot headlabel=invodot]
45    Z->H [arrowhead=open headlabel=open]
46    Z->I [arrowhead=halfopen headlabel=halfopen arrowtail=inv taillabel=sametail]
47    Z->J [arrowhead=empty headlabel=empty]
48    Z->K [arrowhead=invempty headlabel=invempty]
49    Z->L [arrowhead=diamond headlabel=diamond]
50    Z->M [arrowhead=odiamond headlabel=odiamond]
51    Z->N [arrowhead=box headlabel=box]
52    Z->O [arrowhead=obox headlabel=obox]
53    Z->P [arrowhead=tee headlabel=tee]
54    Z->Q [arrowhead=crow headlabel=crow]
55  }
56}
57