 The information that \(A\) and that \(B\) is carried by the situations \(s_1, s_2\ldots\). and the information encoded by the constraint is carried by an information channel \(c\). Given this, Barwise’s evaluation condition for a constraint is as follows (the condition is given here in Barwise’s notation from his later work on conditionals, although in earlier writings such conditions appeared in the notation given in  section 2.2  above): 