 As stressed by Bartsch 1973 (cf. Horn 1978; Horn 1989, Chapter 5), when there are only two alternatives in a given context, as in the case of neg-raising, the denial of one (I don’t believe it will rain) amounts to the assertion of the other (I believe it won’t rain). The relevant reasoning is an instance of the disjunctive syllogism pattern in (11), as seen in (12), where \(F\) represents a propositional attitude and \(a\) the subject of that attitude.