Description: Define negated membership as binary relation. Analogous to df-eprel (the membership relation). (Contributed by AV, 26-Dec-2021)
| Ref | Expression | ||
|---|---|---|---|
| Assertion | df-nelbr | |- e// = { <. x , y >. | -. x e. y } |
| Step | Hyp | Ref | Expression |
|---|---|---|---|
| 0 | cnelbr | |- e// |
|
| 1 | vx | |- x |
|
| 2 | vy | |- y |
|
| 3 | 1 | cv | |- x |
| 4 | 2 | cv | |- y |
| 5 | 3 4 | wcel | |- x e. y |
| 6 | 5 | wn | |- -. x e. y |
| 7 | 6 1 2 | copab | |- { <. x , y >. | -. x e. y } |
| 8 | 0 7 | wceq | |- e// = { <. x , y >. | -. x e. y } |