The search for absolute infinity

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The discussion focuses on the quest to axiomatize a universal set without contradictions, particularly addressing Russell's paradox. Two potential approaches are proposed: modifying the subsets axiom or adopting ternary logic to redefine axioms. The use of ternary logic suggests that certain tautologies in classical logic do not hold, allowing for a re-examination of foundational axioms like extensionality and subsets. The conversation also explores the implications of self-awareness in mathematical structures, particularly regarding a universal set, and how this relates to concepts of awareness and existence in a mathematical context. Ultimately, the thread examines the intersection of set theory, logic, and the nature of infinity.
  • #121
Here is some stuff for you then:

as collection is not a set if given any cardinal A, there is a subset of cardinality greater than A.

this is why there is no set of all sets in ZF - if there were it would contain a set of card A for any A, but then it must contain P(A) which has card strictly greater than A. or if you like there is no maximal cardinal. you should probably look up weakly/strongly unreachable cardinals.

as it is what you appear to be axiomatizing is that the class of all things is called a 'set' because you aren't going to require it to satisfy any pesky things like the other axioms. (defining P(X) for all X but the universal set.
 
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  • #122
thank you for your insights. some questions/comments...

Originally posted by matt grime
Here is some stuff for you then:

as collection is not a set if given any cardinal A, there is a subset of cardinality greater than A.
in tuzfc, U passes this test for setness because of theorem 3 on page 5.

this is why there is no set of all sets in ZF - if there were it would contain a set of card A for any A, but then it must contain P(A) which has card strictly greater than A. or if you like there is no maximal cardinal. you should probably look up weakly/strongly unreachable cardinals.
i want to reiterate that I'm not saying ZF allows for U. I'm saying what you know, i think, which is that one must change things around in order to have a U. also, since P(x)=U iff x=U implies that U cannot be arrived at from a lessor cardinal, proving that it is inaccessible in some sense. hence certain other axioms about inaccessible cardinals may be derivable from my system. however, proofs of relative consistency are way beyond my current understanding; for one thing, it would have to involve passage from a binary logic to ternary logic and/or a combination of the two.

keep in mind that whether or not you like this system, as long as it is consistent, and that remains to be fully seen, imo, it is mathematically sound. what the observer must decide is whether it is useful or not useful and/or interesting or not interesting. that is all. i think that the way i squeezed out the universal set by throwing together a definition of the circle connective would be totally repulsive to some people. but hey, it generalized the biconditional in binary logic and I'm free to generalize it any way i want. such generalizations are either useful or not.

as it is what you appear to be axiomatizing is that the class of all things is called a 'set' because you aren't going to require it to satisfy any pesky things like the other axioms. (defining P(X) for all X but the universal set.

i dont' see why the universal set can't have a powerset. it just so happens to be identical to itself, as theorem 2 on page 5 shows. then theorem 2B shows that if P(x)=U then x=U which i find very satisfying. i do see your point in terms of U not satisfying the foundations axiom but that is the exception and not the rule. for example, one can have a set like this {U} from the pair set axiom and one can take the sum set of U. one can have a choice set for U with no apparent contradiction. etc... I've thought about this a bit and i think the infinity axiom is independent of the universal set axiom; i used to suspect that it was derivable from the unviersal set axiom but i no longer think it is. i need to learn more about forcing and such to really accomplish something non-elementary, i think. if i could prove the relative consistency of tuzfc and zfc then i would be most pleased...
 
  • #123
None of the things I've said should be construed as a 'this is absolutely wrong' as a theory, because I@ve not had time to read and understand it. they are observations about style, points about proofs, and some of the possible problems I can imagine going wrong - but you appear to have thought them through already.
 
  • #124
appearances can be decieving! ;P
 
  • #125
any thoughts on how U might interact with ultrafilters?
 
  • #126
i have a new version 10 with the following theorem:

if f maps x onto P(x) then P(x) contains at least one fuzzy element, ie, x contains at least one fuzzy subset.

the contrapositive of this is that if x does not contain at least one fuzzy subset then there is no map from x onto P(x).

U=P(U) does contain a fuzzy element, namely the S in russell's 'paradox'.

a set is called fuzzy if there is a set whose membership value in that set is neither true nor false. otherwise the set is called crisp.

if you want version 10, then use the same link but replace the 9 with a 10.
 
  • #127
i have version 10-2 which is the current version here:
http://www.alephnulldimension.net/matharticles/

it's not necessarily the first on the list but here's where each update will go. version 10-2 is 103kb and is pdf format.

the addition is this:

1. define [x] to be the set of z in U such that z~x (where z~x means there is a bijection from z to x).

2. the theorem is that for all nonempty x, [x]~U.

eg, there are an equal number of the following three things:
1. sets
2. sets that are singletons
3. sets in bijection with U

it seems like everything that once was a proper class, intuitively, is just now in bijection with U.

is it true that all proper classes are of the same size? well, since the cardinal number of each nonempty set is a proper class, that means i showed that all proper classes are in bijection with U (i think). I'm basing that on the assumption that if a class is in bijection with a set then the class is a set.
 
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  • #128
current version

here is the current version of the universal set article that I'm trying to eventually get published:

http://www.alephnulldimension.net/matharticles/tuzfcver13.pdf

i've trimmed this down now to the essentials. i submitted it to the american mathematical monthly but i sent them a zipped file and they wanted pdf only. before they replied, i spotted something i needed to change so i changed it and here's the version after the change.

here's what happened since last you may have checked it out:
1. x∈x iff x=U. thus, U is a hyperset and U is the only hyperset. this is theorem 0 on page 7.

2. the main thing is that i noticed that if there is a universal set U and a subsets axiom that has the form {y∈x : A(y)} then one can take x to be U to get something that looks like this: {y:A(y)}. this is discussed on pages 4-6.

3. on page 8 there is a corollary which states this: if P(x), the powerset of x, contains no fuzzy sets then there is no function f that maps x onto P(x). (this is the contrapositive of a theorem which states that if there is a function that maps x onto P(x) then P(x) contains at least one fuzzy set.)

if anyone were to write a paper based on this, there are two directions i see it going. one is that with statement 2 above in mind, a bunch of other axioms then follow from the modified subsets axiom. just take {y:y=y} to be the universal set so the universal set follows from the modified subsets axiom. the pair set and powerset axiom also follow, i think, as well as perhaps others. another direction is to look into class theory and see if there is no need for classes all together (see last post on cardinal numbers). finally, an investigation into fuzzy sets would be interesting. are there as many sets as there are fuzzy sets? it seems to me that fuzzy sets would be rare or some such...

so criticism i can use would be greatly appreciated as i try to prepare this for submission. if you've been published yourself, any advice on how to go about doing it would also be immensely useful... for matt grime and hurkyl, i want to add you to the aknowledgements list so send me your real name iff you want to be aknowledged. i suppose i'll also plug the PF itself but that's iff it is publishable! i hope I'm not deluding myself or nothin...
 
  • #129
firstly i do not wish any mention of my name in the acknowledgments; it wouldn't do you any good, nor me, I am not a set theorist, and have no desire for my name to appear anywhere in that area.

secondly, you talk about thing like is it true all proper classes are aof the same size, well they don't have a size, except bigger than any cardinal. There can be no bijections between them because there are no functions between them (in ZF) as that would require them to be a set. you'd have to define functions without reference to sets and that would no longer be in ZF
 
  • #130
i didn't know that's what aknowledgements were for, to do someone good (me if i acknowledged a big time set theorist or the aknowledgee). it was just the expression of the intent to recognize your effort to correct the theory. thanks for your contributions.

second, why can't you have a "class function" whose "domain" and "range" are proper classes? this isn't a big deal though because the article doesn't talk about proper classes though it does state that there is a bijection from the set of all nonempty sets having the same cardinality and the universal set.
 
  • #131
According to string theory, the uncertainty in position is given by:

Dx < h/Dp + C*Dp

Which points towards a type of "discrete" spacetime?


Dx and Dp are the uncertainties in position and momentum, represented as probabiliuty distributions; h is Planck's constant and C is another constant related to the Planck scale.

There is a minimum size that can be probed in string theory. An absolute limit to the precision that any object can be located in space. Ergo, according to M-theory, space cannot be continuous; an infinite amount of information cannot be packed into a finite volume of space.

According to conventional theories, the surface area of the horizon surrounding a black hole, measures its entropy, where entropy is defined as a measure of the number of internal states that the black hole can be in without looking different to an outside observer, who must measure only mass, rotation, and charge. Another theory states that the maximum entropy of any closed region of space can never exceed one quarter of the area of the circumscribing surface, with the entropy being the measure of the total information contained by the system.

S' = S_m + A/4

So the "black hole" theorists came to realize that the information associated with all phenomena in the three dimensional world, can be stored on a two dimensional boundary, analogous to the storing of a holographic image.

The set of all dogs is itself "not" a dog. It is not a member of itself. Sets that are not members of themselves leads to a contradiction in the construction of a universal set. The "set of all sets" cannot exist under these limiting conditions.

A definition of "Algorithm":

http://education.yahoo.com/search/ref?p=algorithm



A step-by-step problem-solving procedure, especially an established, recursive computational procedure for solving a problem in a finite number of steps.


2^x = x is a recursion

2^x = x

then

2^[2^x] = x

2^[2^[2^x]] = x

2^[2^[2^[2^x]]] = x

etc.

DNA is also defined as an algorithm. A finite set? of instructions, a step by step problem solving procedure.

The information contained in DNA can construct a carbon based life form.

So the "DNA" contains the life form analogously to the way a blueprint contains a house.

The life form contains the DNA in the topological sense, while the DNA contains the life form in the "abstract" sense.

The Universal Algorithm contains the Universe in the abstract sense, while the Universe contains the algorithm in the topological sense.

[<-[-><-]->]

The universal set.

The abstract contains the concrete and the concrete contains the abstract.
 
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  • #132
not this again!

a quote from a random passerby reading my paper:

"To do this seriously, we need to develop both a proof theory and a model theory for it, and show soundness and completeness. Only then would we be ready to move on to ZFC, and see what the consequences were, of the change in logic."

anyone know good links to *Online* references in proof theory and model theory?

apparently, the system i "invented" was developed previously by kleene and his three-valued logic system. so maybe i can steal -- i mean reference -- his ideas regarding a model theory and a proof theory.

the passerby wants to use this three valued logic, including the new connective that generalizes iff, to see if the continuum hypothesis is decidable. my wild guess is that CH is true for crisp sets and false for fuzzy sets and i guess what i mean by that is partly that there might be a fuzzy set might have cardinality less than c but equal to aleph1. something like that. my main interest is to provide another avenue towards an absolute infinity; if i just knew the results thus far are sound then i could delve more into it...
 
  • #133
Nifty. I can't say I know any references off hand...
 

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