“…The idea is motivated by the fact that available knowledge is usually incomplete and uncertain. Defeasible logic (Moubaiddin & Obeid, 2007, 2008, 2009Moubaiddin, Salah, & Obeid, 2018;Obeid, 1996Obeid, , 2000Obeid, , 2005Obeid & Rao, 2010;Sabri & Obeid, 2016) is appropriate in those situations where we have only partial knowledge of the actual state of affair. Nonmonotonic rule systems offer more expressive capabilities than classical logic rules.…”