theorem Snd0: $ Snd 0 == 0 $;
| Step | Hyp | Ref | Expression |
|---|---|---|---|
| 1 | eq0al | Snd 0 == 0 <-> A. x ~x e. Snd 0 |
|
| 2 | elSnd | x e. Snd 0 <-> b1 x e. 0 |
|
| 3 | el02 | ~b1 x e. 0 |
|
| 4 | 2, 3 | mtbir | ~x e. Snd 0 |
| 5 | 4 | ax_gen | A. x ~x e. Snd 0 |
| 6 | 1, 5 | mpbir | Snd 0 == 0 |