Description: An example for the membership relation. (Contributed by AV, 19-Jun-2022)
| Ref | Expression | ||
|---|---|---|---|
| Assertion | 0sn0ep | |- (/) _E { (/) } | 
| Step | Hyp | Ref | Expression | 
|---|---|---|---|
| 1 | 0ex | |- (/) e. _V | |
| 2 | 1 | snid |  |-  (/) e. { (/) } | 
| 3 | snex |  |-  { (/) } e. _V | |
| 4 | 3 | epeli |  |-  ( (/) _E { (/) } <-> (/) e. { (/) } ) | 
| 5 | 2 4 | mpbir |  |-  (/) _E { (/) } |