theorem nfsapp {x: nat} (F: set x) (a: nat x):
$ FS/ x F $ >
$ FN/ x a $ >
$ FS/ x F @@ a $;
| Step | Hyp | Ref | Expression |
|---|---|---|---|
| 1 | hyp h1 | FS/ x F |
|
| 2 | hyp h2 | FN/ x a |
|
| 3 | nfnv | FN/ x a1 |
|
| 4 | 2, 3 | nfpr | FN/ x a, a1 |
| 5 | 1, 4 | nfrapp | FS/ x F @' (a, a1) |
| 6 | 5 | nfsab | FS/ x S\ a1, F @' (a, a1) |
| 7 | 6 | conv sapp | FS/ x F @@ a |