digraph G {
  row1 [shape=none, label=""]

  A [label="000"]
  A -> Al [label="L"]
  Al [label="VERIFY"]
  A -> Ar [label="R"]
  Ar [label="SKIP"]

  B [label="001"]
  B -> Bl [label="L"]
  Bl [label="VERIFY"]
  B -> Br [label="R"]
  Br [label="VERIFY"]

  { rank = same; row1; A; B; }

  C [label="010"]
  C -> Cl [label="L"]
  Cl [label="VERIFY"]
  C -> Cr [label="R"]
  Cr [label="DESCEND"]
  Cr -> Crl
  Crl [label="..."]
  Cr -> Crr
  Crr [label="..."]

  D [label="011"]
  D -> Dl [label="L"]
  Dl [label="DESCEND"]
  Dl -> Dll
  Dll [label="..."]
  Dl -> Dlr
  Dlr [label="..."]
  D -> Dr [label="R"]
  Dr [label="SKIP"]

  E [label="100"]
  E -> El [label="L"]
  El [label="DESCEND"]
  El -> Ell
  Ell [label="..."]
  El -> Elr
  Elr [label="..."]
  E -> Er [label="R"]
  Er [label="VERIFY"]

  row1 -> invis [style=invis]
  invis [shape=none, label=""]
  invis -> C [style=invis]
  { rank = same; C; D; E; }

  F [label="101"]
  F -> Fl [label="L"]
  Fl [label="DESCEND"]
  Fl -> Fll
  Fll [label="..."]
  Fl -> Flr
  Flr [label="..."]
  F -> Fr [label="R"]
  Fr [label="DESCEND"]
  Fr -> Frl
  Frl [label="..."]
  Fr -> Frr
  Frr [label="..."]

  G [label="110"]
  G -> Gl [label="L"]
  Gl [label="SKIP"]
  G -> Gr [label="R"]
  Gr [label="VERIFY"]

  H [label="111"]
  H -> Hl [label="L"]
  Hl [label="SKIP"]
  H -> Hr [label="R"]
  Hr [label="DESCEND"]
  Hr -> Hrl
  Hrl [label="..."]
  Hr -> Hrr
  Hrr [label="..."]

  Crl -> F [style=invis]
  { rank = same; F; G; H; }
}
