 To consider an example of such a grounding relationship, let us assume that standard set theory is necessarily true, and that existence is a local property. (If one thinks that existence is not a local property, perhaps because one thinks that existence is the non-local quantificational property of being such that, among all the things there are, there is something that is identical to one, replace existence with the property of being such that, among all the parts of one, there is something identical to one, which is intuitively local.) Let us also assume the common (though not universal) view that members of sets are not literally parts of those sets. (See Lewis (1986a) for an example of a prominent theory of sets that denies members of sets are parts of those sets.) Given these assumptions, it is plausible that the fact that  \(\{Obama\}\) exists is grounded by the fact that Obama exists. However, if this is correct, then, since the fact that Obama exists has a constituent that is not part of \(\{Obama\}\),  it follows that Rosen’s account falsely classifies existence as a non-local property.