 A preferential consequence relation \(\nc\) that satisfies Rational Monotony is called a rational consequence relation. These are characterized by ranked structures which are preferential structures \(S = (\Omega, \prec)\) for which \(\prec\) is modular, i.e., for all \(M, M', M'' \in \Omega\), if \(M \prec M'\) then either \(M'' \prec M'\) or \(M \prec M''\). One can picture this as follows: models in \(\Omega\) are arranged in linearly ordered levels and the level of a model reflects its degree of normality (its rank). 