User blog comment:Simplicityaboveall/Simplicity/@comment-2033667-20141225175235/@comment-2033667-20141228044115

I can certainly understand why you'd want to keep the intro to sets short, but I still wouldn't agree that the intro you've written is really a sufficient foundation. Already you've been talking about some set theory concepts without defining them, namely ordered tuplets and subsets. If you expect the reader to be already familiar with the basics of set theory, that's fine -- just be sure to say this explicitly, and maybe point them to some resources to help catch up.