I quote from the talk page:
In the image caption of the Minkowski addition (and anywhere else), only mathematical variables should be italicized. For example Q1+Q2=[1,3]×[1,3] should be Q1+Q2=[1,3]×[1,3].

I'll check this. LaTeX uses different conventions.
I don't think so. Even if it does, WP:MOSMATH is quite explicit about this (see especially the subsubsection "Variables"). Jakob.scholbach (talk) 
I followed your suggestions. I am sorry if I missed any wrongly italicized sets. Also, I consistently used the WP-hypertext formatting, and removed all LaTeX, for consistency. Kiefer.Wolfowitz (talk) 
Done! Kiefer.Wolfowitz (talk) 

End of quotation.