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Zuhair Al-Johar
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It's known that ZF proves that for every set $x$ there exists a set $H_x$ of all sets that are hereditarily strictly subnumerous to $x$. [see here]. Now is the following principle equivalent with choice over the rest of axioms of ZF?

For every set $x$, there exists aEvery set $y$ such that: $x$ is subnumerous to $H_y$$H_x$.

By "subnumerous to" its meant, as usual, possessing an injection towards; and "strictly subnumerous" means, as usual, existence of subnumerousity without existence of a bijection.

It's known that ZF proves that for every set $x$ there exists a set $H_x$ of all sets that are hereditarily strictly subnumerous to $x$. [see here]. Now is the following principle equivalent with choice over the rest of axioms of ZF?

For every set $x$, there exists a set $y$ such that: $x$ is subnumerous to $H_y$.

By "subnumerous to" its meant, as usual, possessing an injection towards; and "strictly subnumerous" means, as usual, existence of subnumerousity without existence of a bijection.

It's known that ZF proves that for every set $x$ there exists a set $H_x$ of all sets that are hereditarily strictly subnumerous to $x$. [see here]. Now is the following principle equivalent with choice over the rest of axioms of ZF?

Every set $x$ is subnumerous to $H_x$.

By "subnumerous to" its meant, as usual, possessing an injection towards; and "strictly subnumerous" means, as usual, existence of subnumerousity without existence of a bijection.

Source Link
Zuhair Al-Johar
  • 11.3k
  • 1
  • 13
  • 47

Is having injection to hereditarily size sets equivalent with choice over ZF?

It's known that ZF proves that for every set $x$ there exists a set $H_x$ of all sets that are hereditarily strictly subnumerous to $x$. [see here]. Now is the following principle equivalent with choice over the rest of axioms of ZF?

For every set $x$, there exists a set $y$ such that: $x$ is subnumerous to $H_y$.

By "subnumerous to" its meant, as usual, possessing an injection towards; and "strictly subnumerous" means, as usual, existence of subnumerousity without existence of a bijection.