C . ▁players ▁Category : Pl atan ias ▁F . C . ▁players ▁Category : Associ ation ▁football ▁mid field ers <0x0A> </s> ▁In ▁descript ive ▁set ▁theory , ▁the ▁Kle ene – Br ou wer ▁order ▁or ▁L us in – S ier pi ński ▁order ▁is ▁a ▁linear ▁order ▁on ▁finite ▁sequences ▁over ▁some ▁linear ly ▁ordered ▁set ▁, ▁that ▁diff ers ▁from ▁the ▁more ▁commonly ▁used ▁lex ic ographic ▁order ▁in ▁how ▁it ▁handles ▁the ▁case ▁when ▁one ▁sequence ▁is ▁a ▁prefix ▁of ▁the ▁other . ▁In ▁the ▁Kle ene – Br ou wer ▁order , ▁the ▁prefix ▁is ▁later ▁than ▁the ▁longer ▁sequence ▁containing ▁it , ▁rather ▁than ▁earlier . ▁ ▁The ▁Kle ene – Br ou wer ▁order ▁general izes ▁the ▁notion ▁of ▁a ▁post order ▁travers al ▁from ▁finite ▁trees ▁to ▁trees ▁that ▁are ▁not ▁necessarily ▁finite . ▁For ▁trees ▁over ▁a ▁well - ordered ▁set , ▁ ▁the ▁Kle ene – Br ou wer ▁order ▁is ▁itself ▁a ▁well - order ing ▁if ▁and ▁only ▁if ▁the ▁tree ▁has ▁no ▁infinite ▁branch . ▁It ▁is ▁named ▁after ▁Stephen ▁Cole ▁Kle ene , ▁L uit zen ▁Eg bert us ▁Jan ▁Br ou wer , ▁Nikol ai ▁Lu zin , ▁and ▁W ac ław ▁S ier pi ński . ▁ ▁Definition ▁If ▁ ▁and ▁ ▁are ▁finite ▁sequences ▁of ▁elements ▁from ▁, ▁we ▁say ▁that ▁ ▁when ▁there ▁is ▁an ▁ ▁such ▁that ▁either : ▁▁ ▁and ▁ ▁is ▁defined ▁but ▁ ▁is ▁undefined ▁( i . e