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