Description: Ordered pair membership in an ordered pair class abstraction. (Contributed by Mario Carneiro, 19-Dec-2013)
| Ref | Expression | ||
|---|---|---|---|
| Hypothesis | opelopabga.1 | ||
| Assertion | opelopab2a |
| Step | Hyp | Ref | Expression |
|---|---|---|---|
| 1 | opelopabga.1 | ||
| 2 | eleq1 | ||
| 3 | eleq1 | ||
| 4 | 2 3 | bi2anan9 | |
| 5 | 4 1 | anbi12d | |
| 6 | 5 | opelopabga | |
| 7 | 6 | bianabs |