wolffd@0: digraph G {
wolffd@0:   // leave some space for the head/taillabels
wolffd@0:   graph [ranksep=1.5 splines=true overlap=false]
wolffd@0: 
wolffd@0:   // to avoid confusion, remember this:
wolffd@0:   // it's spelt tail/head, but it's read start/end
wolffd@0: 
wolffd@0:   // emphasize theatrically
wolffd@0:   // show only explicitly given head/tails
wolffd@0:   // put head/tail labels farther from the node
wolffd@0: //  edge [arrowsize=2 dir=none labeldistance=3]
wolffd@0:   edge [dir=none labeldistance=3]
wolffd@0: 
wolffd@0:   // not interested in node labels
wolffd@0:   node [shape=circle width=0.5 label=""]
wolffd@0: 
wolffd@0:   {
wolffd@0:     edge [samehead=ahead samearrowhead=1]
wolffd@0:     a->Z [arrowtail=none taillabel=none]
wolffd@0:     b->Z [arrowtail=normal taillabel=normal]
wolffd@0:     c->Z [arrowtail=inv taillabel=inv]
wolffd@0:     d->Z [arrowtail=dot taillabel=dot]
wolffd@0:     e->Z [arrowtail=odot taillabel=odot]
wolffd@0:     f->Z [arrowtail=invdot taillabel=invdot]
wolffd@0:     g->Z [arrowtail=invodot taillabel=invodot]
wolffd@0:     h->Z [arrowtail=open taillabel=open]
wolffd@0:     i->Z [arrowtail=halfopen taillabel=halfopen arrowhead=inv headlabel=samehead]
wolffd@0:     j->Z [arrowtail=empty taillabel=empty]
wolffd@0:     k->Z [arrowtail=invempty taillabel=invempty]
wolffd@0:     l->Z [arrowtail=diamond taillabel=diamond]
wolffd@0:     m->Z [arrowtail=odiamond taillabel=odiamond]
wolffd@0:     n->Z [arrowtail=box taillabel=box]
wolffd@0:     o->Z [arrowtail=obox taillabel=obox]
wolffd@0:     p->Z [arrowtail=tee taillabel=tee]
wolffd@0:     q->Z [arrowtail=crow taillabel=crow]
wolffd@0:   }
wolffd@0:   {
wolffd@0:     edge [sametail=atail samearrowtail=1]
wolffd@0:     Z->A [arrowhead=none headlabel=none]
wolffd@0:     Z->B [arrowhead=normal headlabel=normal]
wolffd@0:     Z->C [arrowhead=inv headlabel=inv]
wolffd@0:     Z->D [arrowhead=dot headlabel=dot]
wolffd@0:     Z->E [arrowhead=odot headlabel=odot]
wolffd@0:     Z->F [arrowhead=invdot headlabel=invdot]
wolffd@0:     Z->G [arrowhead=invodot headlabel=invodot]
wolffd@0:     Z->H [arrowhead=open headlabel=open]
wolffd@0:     Z->I [arrowhead=halfopen headlabel=halfopen arrowtail=inv taillabel=sametail]
wolffd@0:     Z->J [arrowhead=empty headlabel=empty]
wolffd@0:     Z->K [arrowhead=invempty headlabel=invempty]
wolffd@0:     Z->L [arrowhead=diamond headlabel=diamond]
wolffd@0:     Z->M [arrowhead=odiamond headlabel=odiamond]
wolffd@0:     Z->N [arrowhead=box headlabel=box]
wolffd@0:     Z->O [arrowhead=obox headlabel=obox]
wolffd@0:     Z->P [arrowhead=tee headlabel=tee]
wolffd@0:     Z->Q [arrowhead=crow headlabel=crow]
wolffd@0:   }
wolffd@0: }