something that overlaps all and only those things that overlap some of the Xsvs
something that has the Xs as parts and no part disjoint from the Xs.
We also resumed a discussion we had last year about who should count as anti-extensionalist, allowing that there be two non-atomic things sharing all proper parts. Varzi mentions Wiggins 1980, but as Marta Campdelacreu pointed out, for a Wigginsian arguably the head of the cat is part of it, but not of a ‘mere’ fusion of its body cells, right? Any other candidates?