digraph { node[shape=record]; rankdir=LR; l1[label="{ 5| }"]; l2[label="{ 10| }"]; {node[shape=point height=0] invisible_start invisible_end} a -> l1:n; b -> l2:n; invisible_start:n -> l1[arrowtail=none]; invisible_start:s -> invisible_end:s[dir=none]; l1:next:c -> l2:data; l2:next:c -> invisible_end:n[arrowhead=none]; }