Description: Equality with an ordered pair. (Contributed by NM, 15-Dec-2008) (Revised by Mario Carneiro, 23-Feb-2014)
Ref | Expression | ||
---|---|---|---|
Assertion | eqopi | |
Step | Hyp | Ref | Expression |
---|---|---|---|
1 | xpss | |
|
2 | 1 | sseli | |
3 | elxp6 | |
|
4 | 3 | simplbi | |
5 | opeq12 | |
|
6 | 4 5 | sylan9eq | |
7 | 2 6 | sylan | |