Talk:Set Difference with Proper Subset

GFauxPas, I don't think making this theorem weaker than it needs to be is the solution to the definition problem. --Dfeuer (talk) 07:43, 4 March 2013 (UTC)

Non-Empty?
Does the proof really need to be specified as "non-empty"? If $S = \varnothing$ the proof holds vacuously, as there are no proper subsets of $\varnothing$. --prime mover (talk) 08:40, 4 March 2013 (UTC)


 * Oh, that's a good point. I was probably having any imaginable application in mind instead of maximal generality. Feel free to change it back - sorry. &mdash; Lord_Farin (talk) 08:42, 4 March 2013 (UTC)