Description: The element of the disjoint elements class and the disjoint elementhood predicate are the same, that is ( A e. ElDisjs <-> ElDisj A ) when A is a set. (Contributed by Peter Mazsa, 23-Jul-2023)
| Ref | Expression | ||
|---|---|---|---|
| Assertion | eleldisjseldisj |
| Step | Hyp | Ref | Expression |
|---|---|---|---|
| 1 | eleldisjs | ||
| 2 | cnvepresex | ||
| 3 | eldisjsdisj | ||
| 4 | 2 3 | syl | |
| 5 | 1 4 | bitrd | |
| 6 | df-eldisj | ||
| 7 | 5 6 | bitr4di |