 Such facts centrally motivate Kratzer’s account of conditionals as restrictors of modal operators (Kratzer (2012), inspired by D. Lewis 1975). As Kratzer (1991, pp. 468–469) puts it, “there is a very close relationship between if-clauses and operators like must”, and more specifically “for each world, the if-clause has the function of restricting the set of worlds which are accessible from that world”.