Description: Ordered pair element in an intersection with Cartesian product. (Contributed by Peter Mazsa, 21-Jul-2019)
Ref | Expression | ||
---|---|---|---|
Assertion | opelinxp | |
Step | Hyp | Ref | Expression |
---|---|---|---|
1 | brinxp2 | |
|
2 | df-br | |
|
3 | df-br | |
|
4 | 3 | anbi2i | |
5 | 1 2 4 | 3bitr3i | |