HatRack's second definition is about an existing set of all things that do not exist (X≠X).
Let's take a close look at my definition and what it says:
Let {} be the set of ONLY those elements X where X ≠ X.
You claim that my definition is that of an existent set of all things that do not exist. Okay.
But, notice that I also used the word ONLY in my definition. Thus, in addition to containing all things that do not exist, it has the property that it contains ONLY things that do not exist. So, what conclusions can we draw about what elements do exist in the set I am defining? Well, let's have a closer look at these two properties of my set:
(1)
All things that do not exist are in my set: Since non-existent things are... well... non-existent, we are lead to the conclusion that this property gives no assertion about what is in the set and what is not.
(2)
Only things that do not exist are in my set: This tells us that anything which does exist cannot be in the set. In other words, no existent things can be in the set. In other words, the set does not contain any existent things. In other words, it is the
empty set.
Right here is where the defense of my definition ends. I have just shown, in far more detail than is necessary, that it is the definition of the empty set. But, I'll respond to the rest anyway.
HatRack's first definition is about an existing set of all existing things (X=X) that are not its members, where one of the existing sets that are not members of that existing set, is the defined set, or in other words, the defined set is used in order to define itself as a part of its own definition, which is a circular reasoning.
Let's just ignore the first definition altogether, I'm fine sticking with the second only.
HatRack's first and second definitions are not the same definition, exactly as non-existing thing is not the same as an existing thing.
First-order logic would disagree with you. But, like I said, I'm fine with ignoring the first definition.
Furthermore HatRack's second definition is weak and trivial w.r.t the first definition, because it explicitly defines an existing set only by non-existing things.
You can say what you want about it, that doesn't change the fact that it is the definition of the empty set, as I have shown.
doronshadmi said:
Oh, great comeback! Doron, over the last 2 pages of this thread, you have been arguing against the single most stupid and trivial concept in all of mathematics. You've come up with increasingly dumber reasons as to why the empty set does not exist, and you've been shown to be wrong every time. You have also embarrassingly displayed your complete lack of ability to grasp basic logic numerous times.
This has nothing to do with mathematics and everything to do with the fact that you just
cannot admit to being wrong. You would rather descend into the lowest depths of stupidity and completely make a mockery of whatever intelligence you do have than admit to defeat. Mathematics is the most purest and beautiful field of study we have, and you'll sadly never be able to experience it due to your own unrelenting stubbornness.