3 ms·
That may be the border of my english-understanding, but i can prove non-existence of certain things (are they entities?). Since this is currently my seminar-re
by LeanderK 10y ago
That may be the border of my english-understanding, but i can prove non-existence of certain things (are they entities?).
Since this is currently my seminar-research topic: In the Zermelo–Fraenkel set theory there is only one Urelement.
I can prove the non-existence of another Urelement not equal to the Urelement.
Since i only care about Zermelo–Fraenkel, i can define Urelemente as things inside the Zermelo–Fraenkel set theory that are not sets themselves but elements of a set. And there is only one element that satisfies this definition. Every other thing is not a Urelement, since it does not satisfy the definition.
- drdeca 10y agoI don't understand. Is that the proof? I don't understand the proof. If A is an Urelement, and B is an Urelement, ... I don't see a contradiction in A is an element of C, and B is not an element of C? I mean, I defer to your research, but I do not understand...
- deleted 10y ago[deleted]
- AndrewKemendo 10y agoMy point is really about the impossibility of proving a universal negative. Russell's Teapot is instructive here.
- wuthefwasthat 10y agoYou say it's impossible to prove a universal negative? I'd love to see a proof of that