With no explanation, label text_A→text_B with either "not_related" or "related".
text_A: Tim Henman is World number 4 on the ATP rankings.
text_B: Deltocymatocera is an involute cymatoceratid -LRB- Nautilioidea-Nautilida -RRB- with broadly arched whorl sides , strongly convergent on a narrow venter that bears a slight , rounded , keel-like ridge , and with no distinct ventro-latera shoulders .. Nautilida. Nautilida. cymatoceratid. Cymatoceratidae. Sides bear cymatoceratid ribs that bifurcate near the middle of the whorl sides , but do not cross the venter .. cymatoceratid. Cymatoceratidae. The suture has a somewhat pointed ventral saddle , broad lateral lobes -LRB- one on each side -RRB- and prominent saddles on the umbilical shoulders -LRB- again , one per side -RRB- .. The position of the siphuncle in undetermined .. Deltocymatocers is probably derived form Cymatoceras by a rounding of the ventro-lateral shoulders resulting in a narrowing of the venter , coupled with the development of a pointed ventral saddle .. Cymatoceras. Cymatoceras. Eucymatoceras from the Lower Cretaceous is similar , except for lacking the vernal keel .. Eucymatoceras. Eucymatoceras. Contemporary , Upper Cretaceous Epicymatoceras is involute , discoidal .. Epicymatoceras. Epicymatoceras. Deltoidonautiluds with its similar name , and converging sides , belongs to the Hercoglossidae .. Deltoidonautiluds. Deltoidonautiluds. Hercoglossidae. Hercoglossidae
not_related.