▁J ude a ▁Pear l ▁( 1 9 8 8 a , ▁chapter ▁ 9 ; ▁ 1 9 8 8 b ▁and ▁ 1 9 9 0 ) ▁has ▁argued ▁that ▁it ▁is ▁mis leading ▁to ▁interpret ▁belief ▁functions ▁as ▁representing ▁either ▁“ prob abilities ▁of ▁an ▁event ,” ▁or ▁“ the ▁confidence ▁one ▁has ▁in ▁the ▁prob abilities ▁assigned ▁to ▁various ▁out comes ,” ▁or ▁“ de gre es ▁of ▁belief ▁( or ▁confidence , ▁or ▁trust ) ▁in ▁a ▁proposition ,” ▁or ▁“ deg ree ▁of ▁ignor ance ▁in ▁a ▁situation .” ▁Instead , ▁belief ▁functions ▁represent ▁the ▁probability ▁that ▁a ▁given ▁proposition ▁is ▁prov able ▁from ▁a ▁set ▁of ▁other ▁propos itions , ▁to ▁which ▁prob abilities ▁are ▁assigned . ▁Conf using ▁prob abilities ▁of ▁truth ▁with ▁prob abilities ▁of ▁prov ability ▁may ▁lead ▁to ▁counter int uit ive ▁results ▁in ▁reasoning ▁tasks ▁such ▁as ▁( 1 ) ▁representing ▁incomplete ▁knowledge , ▁( 2 ) ▁belief - up dating ▁and ▁( 3 ) ▁evidence ▁pool ing . ▁He ▁further ▁demonstrated ▁that , ▁if ▁partial ▁knowledge ▁is ▁encoded ▁and ▁updated ▁by ▁belief ▁function ▁methods , ▁the ▁resulting ▁belief s ▁cannot ▁serve ▁as ▁a ▁basis ▁for ▁rational ▁dec isions . ▁ ▁K ł op ote k ▁and ▁W ierz cho ń ▁proposed ▁to ▁interpret ▁the ▁D emp ster – S ha fer ▁theory ▁in ▁terms ▁of ▁statistics ▁of ▁decision ▁tables ▁( of ▁the ▁rough ▁set ▁theory ), ▁where by ▁the ▁operator ▁of ▁combining ▁evidence ▁should ▁be ▁seen ▁as ▁rel ational ▁joining