 where 1 stands for true, 0 for false. At non-normal worlds, formulas of the form £\(A\), with £ a modal, are not evaluated depending on the truth value of \(A\) at other (accessible) worlds, but get assigned their truth value directly: all box-formulas are false and all diamond-formulas are true. In a sense, at non-normal worlds nothing is necessary, and anything is possible. These worlds, however, are deviant only in this respect: their behavior, as far as the extensional connectives are concerned, is quite regular.