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 )