A Four-Valued Logic for Rough Set-Like Approximate Reasoning.

Jan Maluszynski Andrzej Szalas Aida Vitória A Four-Valued Logic for Rough Set-Like Approximate Reasoning. 176-190 2007 6 T. Rough Sets http://dx.doi.org/10.1007/978-3-540-71200-8_11 db/journals/trs/trs6.html#MaluszynskiSV07