Description: Ordered-pair class abstraction defined by a negation. (Contributed by Peter Mazsa, 25-Jun-2019)
Ref | Expression | ||
---|---|---|---|
Assertion | vvdifopab | |
Step | Hyp | Ref | Expression |
---|---|---|---|
1 | opabidw | |
|
2 | 1 | notbii | |
3 | opelvvdif | |
|
4 | 3 | el2v | |
5 | opabidw | |
|
6 | 2 4 5 | 3bitr4i | |
7 | 6 | gen2 | |
8 | relxp | |
|
9 | reldif | |
|
10 | 8 9 | ax-mp | |
11 | relopabv | |
|
12 | nfcv | |
|
13 | nfopab1 | |
|
14 | 12 13 | nfdif | |
15 | nfopab1 | |
|
16 | nfcv | |
|
17 | nfopab2 | |
|
18 | 16 17 | nfdif | |
19 | nfopab2 | |
|
20 | 14 15 18 19 | eqrelf | |
21 | 10 11 20 | mp2an | |
22 | 7 21 | mpbir | |