Skip to main content

All Questions

Filter by
Sorted by
Tagged with
4 votes
0 answers
227 views

stating large cardinal axioms in ZF

Can I ask whether there is a good reference for how to state the standard large cardinal axioms in the context of $ZF$? My concern is that it seems that the usual proof that embeddings defined from ...
Rupert's user avatar
  • 2,125
2 votes
0 answers
120 views

How to express Kunen's inconsistency, Reinhardt and Wholeness axioms, by single sentences?

Working in $\sf NBG, $ can we express the property of a class being set theoretically definable, by a single sentence? Like for example, the following way: $$\operatorname {std}(X) \iff \exists x_1 \...
Zuhair Al-Johar's user avatar
4 votes
0 answers
271 views

Can we have full choice prior to Reinhardt cardinals?

Working in $\sf ZF + Reinhardt \ cardinal$, can we have full choice over all stages $V_{\alpha < \kappa}$ where $\kappa$ is the Reinhardt cardinal, i.e., the critical point of the elementary ...
Zuhair Al-Johar's user avatar
1 vote
0 answers
79 views

Can this method let choiceless large cardinals be smaller than cardinals compatible with choice?

Recall question "Can we have this sequence where choice fails and returns?" Can that theory be extended with requiring the $\mathcal V_n$'s to fulfill a choiceless large cardinal extension ...
Zuhair Al-Johar's user avatar
2 votes
1 answer
357 views

Can we interpret Reinhardt cardinals this way?

To the language of set theory add a primitive unary predicate $\operatorname {Universe}$ and a primitive total unary function $j$. Add all axioms of $\sf ZF$ in the language of this theory, i.e. the ...
Zuhair Al-Johar's user avatar
1 vote
2 answers
274 views

Can we iteratively reflect on self elementary embeddable stages of the cumulative hierarchy?

Is it possible to iterate elementary embeddability and reflect on those stages that are elementary embeddable to themselves? The following is a formal capture of that idea: To the language of $\sf ZF$...
Zuhair Al-Johar's user avatar
8 votes
1 answer
1k views

Is there a form of choice that can elude Kunen's inconsistency theorem?

When it is said that Kunen inconsistency theorem proves that given $\sf ZFC$ no elementary embedding can exist from the universe to itself. Most references quote full choice in stating that result, ...
Zuhair Al-Johar's user avatar
3 votes
1 answer
292 views

If we add stratified\acyclic replacement to the wholeness axiom, would that increase its consistency strength?

If we add to the wholeness axiom, the axiom of stratified\acyclic replacement, what would be the consistency state and strength of the resulting theory? The wholeness axiom $\sf WA$, introduced by ...
Zuhair Al-Johar's user avatar