TY - JOUR A1 - Besnard, Philippe A1 - Schaub, Torsten H. T1 - What is a (non-constructive) non-monotone logical system? Y1 - 2000 UR - https://publishup.uni-potsdam.de/frontdoor/index/index/docId/19954 SN - 0304-3975 ER -