Description: Lemma for ackbij2 . (Contributed by Stefan O'Rear, 19-Nov-2014)
Ref | Expression | ||
---|---|---|---|
Assertion | ackbij1lem4 | |- ( A e. _om -> { A } e. ( ~P _om i^i Fin ) ) |
Step | Hyp | Ref | Expression |
---|---|---|---|
1 | snelpwi | |- ( A e. _om -> { A } e. ~P _om ) |
|
2 | snfi | |- { A } e. Fin |
|
3 | 2 | a1i | |- ( A e. _om -> { A } e. Fin ) |
4 | 1 3 | elind | |- ( A e. _om -> { A } e. ( ~P _om i^i Fin ) ) |