00317nam a2200109Ia 4500008004100000040003800041100001900079245004000098260003700138300001700175653001500192211214s9999    xx            000 0 und d  cJayakar Knowledge Resource Centre  aChurchman, C W 0aElements of logic and formal scince  bJ B LIPPINCOTT COaCHICAGOc1951  aVII,337 P p.  aPHILOSOPHY