Description: A numerable infinite set contains a countable subset.MOVABLE (Contributed by Stefan O'Rear, 9-Jul-2015)
Ref | Expression | ||
---|---|---|---|
Assertion | numinfctb | |
Step | Hyp | Ref | Expression |
---|---|---|---|
1 | omelon | |
|
2 | onenon | |
|
3 | 1 2 | ax-mp | |
4 | domtri2 | |
|
5 | 3 4 | mpan | |
6 | isfinite | |
|
7 | 6 | notbii | |
8 | 5 7 | bitr4di | |
9 | 8 | biimpar | |