Very large set axioms over constructive set theories

Fuente: arXiv
Saved in:
Bibliographic Details
Main Authors: Jeon, Hanul, Matthews, Richard
Format: Preprint
Published: 2022
Subjects:
Online Access:
Tags: Add Tag
No Tags, Be the first to tag this record!
_version_ 1866915212197625856
author Jeon, Hanul
Matthews, Richard
author_facet Jeon, Hanul
Matthews, Richard
contents We investigate large set axioms defined in terms of elementary embeddings over constructive set theories, focusing on $\mathsf{IKP}$ and $\mathsf{CZF}$. Most previously studied large set axioms, notably the constructive analogues of large cardinals below $0^\sharp$, have proof-theoretic strength weaker than full Second-order Arithmetic. On the other hand, the situation is dramatically different for those defined via elementary embeddings. We show that by adding to $\mathsf{IKP}$ the basic properties of an elementary embedding $j\colon V\to M$ for $Δ_0$-formulas, which we will denote by $\mathsf{Δ_0\text{-}BTEE}_M$, we obtain the consistency of $\mathsf{ZFC}$ and more. We will also see that the consistency strength of a Reinhardt set exceeds that of $\mathsf{ZF+WA}$. Furthermore, we will define super Reinhardt sets and $\mathsf{TR}$, which is a constructive analogue of $V$ being totally Reinhardt, and prove that their proof-theoretic strength exceeds that of $\mathsf{ZF}$ with choiceless large cardinals.
format Preprint
id arxiv_https___arxiv_org_abs_2204_05831
institution arXiv
publishDate 2022
record_format arxiv
spellingShingle Very large set axioms over constructive set theories
Jeon, Hanul
Matthews, Richard
Logic
Primary 03E70, Secondary 03E55
We investigate large set axioms defined in terms of elementary embeddings over constructive set theories, focusing on $\mathsf{IKP}$ and $\mathsf{CZF}$. Most previously studied large set axioms, notably the constructive analogues of large cardinals below $0^\sharp$, have proof-theoretic strength weaker than full Second-order Arithmetic. On the other hand, the situation is dramatically different for those defined via elementary embeddings. We show that by adding to $\mathsf{IKP}$ the basic properties of an elementary embedding $j\colon V\to M$ for $Δ_0$-formulas, which we will denote by $\mathsf{Δ_0\text{-}BTEE}_M$, we obtain the consistency of $\mathsf{ZFC}$ and more. We will also see that the consistency strength of a Reinhardt set exceeds that of $\mathsf{ZF+WA}$. Furthermore, we will define super Reinhardt sets and $\mathsf{TR}$, which is a constructive analogue of $V$ being totally Reinhardt, and prove that their proof-theoretic strength exceeds that of $\mathsf{ZF}$ with choiceless large cardinals.
title Very large set axioms over constructive set theories
topic Logic
Primary 03E70, Secondary 03E55
url https://arxiv.org/abs/2204.05831