Description: Alternate proof of reex . (Contributed by NM, 30-Jul-2004) (Revised by Mario Carneiro, 23-Aug-2014) (Proof modification is discouraged.) (New usage is discouraged.)
Ref | Expression | ||
---|---|---|---|
Assertion | reexALT | |
Step | Hyp | Ref | Expression |
---|---|---|---|
1 | nnexALT | |
|
2 | qexALT | |
|
3 | 1 2 | rpnnen1 | |
4 | reldom | |
|
5 | 4 | brrelex1i | |
6 | 3 5 | ax-mp | |