Search All of the Math Forum:
Views expressed in these public forums are not endorsed by
NCTM or The Math Forum.


Math Forum
»
Discussions
»
sci.math.*
»
sci.math
Notice: We are no longer accepting new posts, but the forums will continue to be readable.
Topic:
CON(ZF) and the ontology of ZF
Replies:
5
Last Post:
Feb 19, 2013 3:53 AM



fom
Posts:
1,968
Registered:
12/4/12


Re: CON(ZF) and the ontology of ZF
Posted:
Feb 17, 2013 1:40 PM


On 2/17/2013 12:12 PM, Zuhair wrote: > On Feb 17, 11:42 am, fom <fomJ...@nyms.net> wrote: >> >> So, returning to the statements in the opening >> paragraph, it does not surprise me that Zuhair >> may have succeeded in devising a means by which >> to show Con(ZF) relative to MorseKelley set theory. >> MorseKelley set theory as presented in Kelley >> presumes a global axiom of choice. > > The theory that I've presented can actually work without the axiom > of global choice!
I believe this. You represented the forcing methodology directly. And, I am now fairly convinced that that methodology is implicit to the axiom of induction for arithmetic.
Think carefully about how I ended that post. I pointed to a link explaining the relationship of AC to GCH
There is a reason I did that. I do not ascribe to the usual model theory for set theory. It is not logically secure. Very few people like my posts, but this is one attempt at explaining myself on "truth" for set theory.
news://news.giganews.com:119/5bidnemPpsnq13zNnZ2dnUVZ_sOdnZ2d@giganews.com
> > this is done by replacing axiom of Universal limitation by > axiom of direct size limitation. > > To reiterate my theory. It is too simple actually. > > Language: FOL(=,e) > > Definition: Set(x) <> Ey(x e y) > > Axioms: > > 1.Extensionality: (Az. z e x <> z e y) > x=y > 2.Class comprehension: {x Set(x) phi} exists. > 3.Pairing: (Ay. y e x > y=a or y=b) > Set(x) > 4.Hereditary limitation: Set(x) <> Ey. Set(y) & AzeTC(x).z=<y > 5.Size limitation: Set(x) & y=<x > Set(y) > / > > where x =< y <> Ef. f:x>y & f is injective > and TC(x)={yAs. x subset_of s & s is transitive > y e s} > > This proves MKchoice. However it might be stronger than MKchoice? > MK+global choice proves all the above axioms.
In general, I am unfamiliar with MorseKelley. I have read through the appendix of "General Topology", and that does have only global choice. So, I am not certain of your distinctions here and cannot even begin to address the question.



