Metamath Proof Explorer


Theorem fict

Description: A finite set is countable (weaker version of isfinite ). (Contributed by Thierry Arnoux, 27-Mar-2018)

Ref Expression
Assertion fict ⊢ A ∈ Fin → A ≼ ω

Proof

Step Hyp Ref Expression
1 isfinite ⊢ A ∈ Fin ↔ A ≺ ω
2 sdomdom ⊢ A ≺ ω → A ≼ ω
3 1 2 sylbi ⊢ A ∈ Fin → A ≼ ω