 Since (W†) is judged after the slow switch, the initial use of ‘water’ refers to XYZ. But does the second use of ‘water’ refer to XYZ? It seems so, since (W†) is comparing his current imbibing habits with the past. Such a comparison, of course, requires the liquid named in (W†) to be constant. And since the initial use of ‘water’ denotes XYZ, the second use of ‘water’ must also. The upshot is that after the switch, the second clause in (W†) expresses a memory that has “shifted” from water content to a twin water content, as predicted by the compatibilist.