**Description:** A countable set is a set. (Contributed by Thierry Arnoux, 29-Dec-2016)
(Proof shortened by Jim Kingdon, 13-Mar-2023)

Ref | Expression | ||
---|---|---|---|

Assertion | ctex | ⊢ ( 𝐴 ≼ ω → 𝐴 ∈ V ) |

Step | Hyp | Ref | Expression |
---|---|---|---|

1 | reldom | ⊢ Rel ≼ | |

2 | 1 | brrelex1i | ⊢ ( 𝐴 ≼ ω → 𝐴 ∈ V ) |