Description: Lemma 4 for pmtrdifel . (Contributed by AV, 28-Jan-2019)
Ref | Expression | ||
---|---|---|---|
Hypotheses | pmtrdifel.t | |
|
pmtrdifel.r | |
||
pmtrdifel.0 | |
||
Assertion | pmtrdifellem4 | |
Step | Hyp | Ref | Expression |
---|---|---|---|
1 | pmtrdifel.t | |
|
2 | pmtrdifel.r | |
|
3 | pmtrdifel.0 | |
|
4 | 1 2 3 | pmtrdifellem1 | |
5 | eqid | |
|
6 | eqid | |
|
7 | 5 2 6 | pmtrffv | |
8 | 4 7 | sylan | |
9 | eqid | |
|
10 | eqid | |
|
11 | 1 9 10 | symgtrf | |
12 | 11 | sseli | |
13 | 9 10 | symgbasf | |
14 | ffn | |
|
15 | fndifnfp | |
|
16 | ssrab2 | |
|
17 | ssel2 | |
|
18 | eldif | |
|
19 | elsng | |
|
20 | 19 | notbid | |
21 | eqid | |
|
22 | 21 | pm2.24i | |
23 | 20 22 | syl6bi | |
24 | 23 | imp | |
25 | 18 24 | sylbi | |
26 | 17 25 | syl | |
27 | 16 26 | mpan | |
28 | 27 | con2i | |
29 | eleq2 | |
|
30 | 29 | notbid | |
31 | 28 30 | imbitrrid | |
32 | 14 15 31 | 3syl | |
33 | 12 13 32 | 3syl | |
34 | 33 | imp | |
35 | 1 2 3 | pmtrdifellem2 | |
36 | 35 | eleq2d | |
37 | 36 | adantr | |
38 | 34 37 | mtbird | |
39 | 38 | iffalsed | |
40 | 8 39 | eqtrd | |