Description: Coelements on A is a relation. (Contributed by Peter Mazsa, 5-Oct-2021)
| Ref | Expression | ||
|---|---|---|---|
| Assertion | relcoels | |- Rel ~ A |
| Step | Hyp | Ref | Expression |
|---|---|---|---|
| 1 | relcoss | |- Rel ,~ ( `' _E |` A ) |
|
| 2 | df-coels | |- ~ A = ,~ ( `' _E |` A ) |
|
| 3 | 2 | releqi | |- ( Rel ~ A <-> Rel ,~ ( `' _E |` A ) ) |
| 4 | 1 3 | mpbir | |- Rel ~ A |