Talk:Set Difference is Set

Unfortunately, this references Set Difference as Intersection with Relative Complement, which would implicitly assume that is was a set. But this rule holds for classes, too. --Andrew Salmon 21:14, 7 August 2012 (UTC)


 * In principle I think you could reason from the direct definition of 'set difference'; I think this is preferable in any case since we are dealing with the very important basics of reasoning with classes here. It won't be too hard, I think. Maybe put some 'explain' or 'WIP' tag for now so that we don't forget. I suggest postponing the problem until after we are geared up for a canonicalisation of this whole area. --Lord_Farin 21:21, 7 August 2012 (UTC)


 * I just came up with the idea of a general page defining all of the standard set-theoretic things expressible in LST (i.e., with $\in$ only) for classes. Maybe it could be called Operations on Classes; I imagine a structure similar to Combination Theorem for Sequences. --Lord_Farin 19:36, 8 August 2012 (UTC)
 * This page would allow one to cut through the tast of processing the small annoying derivations of an interpretation of a concept for classes through that of $\in$. --Lord_Farin 19:37, 8 August 2012 (UTC)