Description: A finite set is countable (weaker version of isfinite ). (Contributed by Thierry Arnoux, 27-Mar-2018)
Ref | Expression | ||
---|---|---|---|
Assertion | fict | |- ( A e. Fin -> A ~<_ _om ) |
Step | Hyp | Ref | Expression |
---|---|---|---|
1 | isfinite | |- ( A e. Fin <-> A ~< _om ) |
|
2 | sdomdom | |- ( A ~< _om -> A ~<_ _om ) |
|
3 | 1 2 | sylbi | |- ( A e. Fin -> A ~<_ _om ) |