[dustin_archibald]

Originally Posted by Lost

The way I see it, {everything} = {all that exists} + {all that does not exist}

We agree on this one (our initial equations are the same ). I just took it a step more and followed the equation to the next step.

Originally Posted by dustin_archibald

If you wanted to you could say that "everything" is all that exists or does not exist but that would ultimately lead to all things in existence being Everything. If you want to get into sets (please excuse my notation, it's been a while since logic courses):

Definitions and assumptions:

1. A={Non-existence}={}
   1. We say that A is the empty set since it has no items (technically it has all of the items that do not exist).
2. B={Existence}
   1. This set includes all things that have existed, do exist, and will exist (as per my original post)
3. C={Everything}

Calculations:

1. C=A U B
2. C= ø U B
3. C=B
4. {Everything}={Existence}

I would have to say that ultimately Everything encompases all that exists as well as all that does not exist. Perhaps my logic is flawed with the initial assumption that A={Non-existence}={}? Is this set truly empty?

Originally Posted by Lost

After all, without nothingness, how could anything be said to exist? Compared to what?

The theories that I linked to are not intended to be dependent on eachother (which is why they are listed as two theories instead of just inferring one from the other). As such we can define existence using the properties in the Theory of Existence without relying on comparrison to non-existence (nothing):

Something is said to exist if:
a) it affects something
AND/OR
b) something affects it