Description: Obsolete version of dffun6 as of 19-Dec-2024. (Contributed by NM, 9-Mar-1995) (Proof modification is discouraged.) (New usage is discouraged.)
| Ref | Expression | ||
|---|---|---|---|
| Assertion | dffun6OLD | |- ( Fun F <-> ( Rel F /\ A. x E* y x F y ) ) |
| Step | Hyp | Ref | Expression |
|---|---|---|---|
| 1 | nfcv | |- F/_ x F |
|
| 2 | nfcv | |- F/_ y F |
|
| 3 | 1 2 | dffun6f | |- ( Fun F <-> ( Rel F /\ A. x E* y x F y ) ) |