Description: Range of an ordered-pair class abstraction. (Contributed by Thierry Arnoux, 31-Aug-2017)
Ref | Expression | ||
---|---|---|---|
Assertion | opabrn | |
Step | Hyp | Ref | Expression |
---|---|---|---|
1 | dfrn2 | |
|
2 | nfopab2 | |
|
3 | 2 | nfeq2 | |
4 | nfopab1 | |
|
5 | 4 | nfeq2 | |
6 | df-br | |
|
7 | eleq2 | |
|
8 | opabidw | |
|
9 | 7 8 | bitrdi | |
10 | 6 9 | syl5bb | |
11 | 5 10 | exbid | |
12 | 3 11 | abbid | |
13 | 1 12 | eqtrid | |