Description: Obsolete version of nnfi as of 23-Sep-2024. (Contributed by Stefan O'Rear, 21-Mar-2015) (Proof modification is discouraged.) (New usage is discouraged.)
| Ref | Expression | ||
|---|---|---|---|
| Assertion | nnfiOLD | |- ( A e. _om -> A e. Fin ) |
| Step | Hyp | Ref | Expression |
|---|---|---|---|
| 1 | onfin2 | |- _om = ( On i^i Fin ) |
|
| 2 | inss2 | |- ( On i^i Fin ) C_ Fin |
|
| 3 | 1 2 | eqsstri | |- _om C_ Fin |
| 4 | 3 | sseli | |- ( A e. _om -> A e. Fin ) |