  At first, it might look like not much has been accomplished here. All that we did was turn a Problem of 4 clouds into a Problem of 3 clouds, replacing the fusions a + w1 and a + w2 with the new, and oddly behaved, c. But that is to overlook a rather important feature of the remaining proto-clouds. The three remaining proto-clouds can be strictly ordered by the ‘part of’ relation. This was not previously possible, since neither a + w1 nor a + w2 were part of the other. If we adopt the principle that ‘cloud’ is a maximal predicate, so no cloud can be a proper part of another cloud, we now get the conclusion that there is exactly one of the proto-clouds is a cloud, as desired.