 In CL a formula \(\phi\) is entailed by \(\Gamma\) (in signs \(\Gamma \vDash \phi\)) if and only if \(\phi\) is valid in all classical models of \(\Gamma\). An influential idea in NML is to define non-monotonic entailment not in terms of all classical models of \(\Gamma\), but rather in terms of a selection of these models  (Shoham 1987).  Intuitively the idea is to read 