Step |
Hyp |
Ref |
Expression |
1 |
|
disjprgw.1 |
|- ( x = A -> C = D ) |
2 |
|
disjprgw.2 |
|- ( x = B -> C = E ) |
3 |
|
eqeq1 |
|- ( y = A -> ( y = z <-> A = z ) ) |
4 |
|
nfcv |
|- F/_ x A |
5 |
|
nfcv |
|- F/_ x D |
6 |
4 5 1
|
csbhypf |
|- ( y = A -> [_ y / x ]_ C = D ) |
7 |
6
|
ineq1d |
|- ( y = A -> ( [_ y / x ]_ C i^i [_ z / x ]_ C ) = ( D i^i [_ z / x ]_ C ) ) |
8 |
7
|
eqeq1d |
|- ( y = A -> ( ( [_ y / x ]_ C i^i [_ z / x ]_ C ) = (/) <-> ( D i^i [_ z / x ]_ C ) = (/) ) ) |
9 |
3 8
|
orbi12d |
|- ( y = A -> ( ( y = z \/ ( [_ y / x ]_ C i^i [_ z / x ]_ C ) = (/) ) <-> ( A = z \/ ( D i^i [_ z / x ]_ C ) = (/) ) ) ) |
10 |
9
|
ralbidv |
|- ( y = A -> ( A. z e. { A , B } ( y = z \/ ( [_ y / x ]_ C i^i [_ z / x ]_ C ) = (/) ) <-> A. z e. { A , B } ( A = z \/ ( D i^i [_ z / x ]_ C ) = (/) ) ) ) |
11 |
|
eqeq1 |
|- ( y = B -> ( y = z <-> B = z ) ) |
12 |
|
nfcv |
|- F/_ x B |
13 |
|
nfcv |
|- F/_ x E |
14 |
12 13 2
|
csbhypf |
|- ( y = B -> [_ y / x ]_ C = E ) |
15 |
14
|
ineq1d |
|- ( y = B -> ( [_ y / x ]_ C i^i [_ z / x ]_ C ) = ( E i^i [_ z / x ]_ C ) ) |
16 |
15
|
eqeq1d |
|- ( y = B -> ( ( [_ y / x ]_ C i^i [_ z / x ]_ C ) = (/) <-> ( E i^i [_ z / x ]_ C ) = (/) ) ) |
17 |
11 16
|
orbi12d |
|- ( y = B -> ( ( y = z \/ ( [_ y / x ]_ C i^i [_ z / x ]_ C ) = (/) ) <-> ( B = z \/ ( E i^i [_ z / x ]_ C ) = (/) ) ) ) |
18 |
17
|
ralbidv |
|- ( y = B -> ( A. z e. { A , B } ( y = z \/ ( [_ y / x ]_ C i^i [_ z / x ]_ C ) = (/) ) <-> A. z e. { A , B } ( B = z \/ ( E i^i [_ z / x ]_ C ) = (/) ) ) ) |
19 |
10 18
|
ralprg |
|- ( ( A e. V /\ B e. V ) -> ( A. y e. { A , B } A. z e. { A , B } ( y = z \/ ( [_ y / x ]_ C i^i [_ z / x ]_ C ) = (/) ) <-> ( A. z e. { A , B } ( A = z \/ ( D i^i [_ z / x ]_ C ) = (/) ) /\ A. z e. { A , B } ( B = z \/ ( E i^i [_ z / x ]_ C ) = (/) ) ) ) ) |
20 |
19
|
3adant3 |
|- ( ( A e. V /\ B e. V /\ A =/= B ) -> ( A. y e. { A , B } A. z e. { A , B } ( y = z \/ ( [_ y / x ]_ C i^i [_ z / x ]_ C ) = (/) ) <-> ( A. z e. { A , B } ( A = z \/ ( D i^i [_ z / x ]_ C ) = (/) ) /\ A. z e. { A , B } ( B = z \/ ( E i^i [_ z / x ]_ C ) = (/) ) ) ) ) |
21 |
|
id |
|- ( z = A -> z = A ) |
22 |
21
|
eqcomd |
|- ( z = A -> A = z ) |
23 |
22
|
orcd |
|- ( z = A -> ( A = z \/ ( D i^i [_ z / x ]_ C ) = (/) ) ) |
24 |
|
trud |
|- ( z = A -> T. ) |
25 |
23 24
|
2thd |
|- ( z = A -> ( ( A = z \/ ( D i^i [_ z / x ]_ C ) = (/) ) <-> T. ) ) |
26 |
|
eqeq2 |
|- ( z = B -> ( A = z <-> A = B ) ) |
27 |
12 13 2
|
csbhypf |
|- ( z = B -> [_ z / x ]_ C = E ) |
28 |
27
|
ineq2d |
|- ( z = B -> ( D i^i [_ z / x ]_ C ) = ( D i^i E ) ) |
29 |
28
|
eqeq1d |
|- ( z = B -> ( ( D i^i [_ z / x ]_ C ) = (/) <-> ( D i^i E ) = (/) ) ) |
30 |
26 29
|
orbi12d |
|- ( z = B -> ( ( A = z \/ ( D i^i [_ z / x ]_ C ) = (/) ) <-> ( A = B \/ ( D i^i E ) = (/) ) ) ) |
31 |
25 30
|
ralprg |
|- ( ( A e. V /\ B e. V ) -> ( A. z e. { A , B } ( A = z \/ ( D i^i [_ z / x ]_ C ) = (/) ) <-> ( T. /\ ( A = B \/ ( D i^i E ) = (/) ) ) ) ) |
32 |
31
|
3adant3 |
|- ( ( A e. V /\ B e. V /\ A =/= B ) -> ( A. z e. { A , B } ( A = z \/ ( D i^i [_ z / x ]_ C ) = (/) ) <-> ( T. /\ ( A = B \/ ( D i^i E ) = (/) ) ) ) ) |
33 |
|
simp3 |
|- ( ( A e. V /\ B e. V /\ A =/= B ) -> A =/= B ) |
34 |
|
neneq |
|- ( A =/= B -> -. A = B ) |
35 |
|
biorf |
|- ( -. A = B -> ( ( D i^i E ) = (/) <-> ( A = B \/ ( D i^i E ) = (/) ) ) ) |
36 |
33 34 35
|
3syl |
|- ( ( A e. V /\ B e. V /\ A =/= B ) -> ( ( D i^i E ) = (/) <-> ( A = B \/ ( D i^i E ) = (/) ) ) ) |
37 |
|
tru |
|- T. |
38 |
37
|
biantrur |
|- ( ( A = B \/ ( D i^i E ) = (/) ) <-> ( T. /\ ( A = B \/ ( D i^i E ) = (/) ) ) ) |
39 |
36 38
|
bitrdi |
|- ( ( A e. V /\ B e. V /\ A =/= B ) -> ( ( D i^i E ) = (/) <-> ( T. /\ ( A = B \/ ( D i^i E ) = (/) ) ) ) ) |
40 |
32 39
|
bitr4d |
|- ( ( A e. V /\ B e. V /\ A =/= B ) -> ( A. z e. { A , B } ( A = z \/ ( D i^i [_ z / x ]_ C ) = (/) ) <-> ( D i^i E ) = (/) ) ) |
41 |
|
eqeq2 |
|- ( z = A -> ( B = z <-> B = A ) ) |
42 |
|
eqcom |
|- ( B = A <-> A = B ) |
43 |
41 42
|
bitrdi |
|- ( z = A -> ( B = z <-> A = B ) ) |
44 |
4 5 1
|
csbhypf |
|- ( z = A -> [_ z / x ]_ C = D ) |
45 |
44
|
ineq2d |
|- ( z = A -> ( E i^i [_ z / x ]_ C ) = ( E i^i D ) ) |
46 |
|
incom |
|- ( E i^i D ) = ( D i^i E ) |
47 |
45 46
|
eqtrdi |
|- ( z = A -> ( E i^i [_ z / x ]_ C ) = ( D i^i E ) ) |
48 |
47
|
eqeq1d |
|- ( z = A -> ( ( E i^i [_ z / x ]_ C ) = (/) <-> ( D i^i E ) = (/) ) ) |
49 |
43 48
|
orbi12d |
|- ( z = A -> ( ( B = z \/ ( E i^i [_ z / x ]_ C ) = (/) ) <-> ( A = B \/ ( D i^i E ) = (/) ) ) ) |
50 |
|
id |
|- ( z = B -> z = B ) |
51 |
50
|
eqcomd |
|- ( z = B -> B = z ) |
52 |
51
|
orcd |
|- ( z = B -> ( B = z \/ ( E i^i [_ z / x ]_ C ) = (/) ) ) |
53 |
|
trud |
|- ( z = B -> T. ) |
54 |
52 53
|
2thd |
|- ( z = B -> ( ( B = z \/ ( E i^i [_ z / x ]_ C ) = (/) ) <-> T. ) ) |
55 |
49 54
|
ralprg |
|- ( ( A e. V /\ B e. V ) -> ( A. z e. { A , B } ( B = z \/ ( E i^i [_ z / x ]_ C ) = (/) ) <-> ( ( A = B \/ ( D i^i E ) = (/) ) /\ T. ) ) ) |
56 |
55
|
3adant3 |
|- ( ( A e. V /\ B e. V /\ A =/= B ) -> ( A. z e. { A , B } ( B = z \/ ( E i^i [_ z / x ]_ C ) = (/) ) <-> ( ( A = B \/ ( D i^i E ) = (/) ) /\ T. ) ) ) |
57 |
37
|
biantru |
|- ( ( A = B \/ ( D i^i E ) = (/) ) <-> ( ( A = B \/ ( D i^i E ) = (/) ) /\ T. ) ) |
58 |
36 57
|
bitrdi |
|- ( ( A e. V /\ B e. V /\ A =/= B ) -> ( ( D i^i E ) = (/) <-> ( ( A = B \/ ( D i^i E ) = (/) ) /\ T. ) ) ) |
59 |
56 58
|
bitr4d |
|- ( ( A e. V /\ B e. V /\ A =/= B ) -> ( A. z e. { A , B } ( B = z \/ ( E i^i [_ z / x ]_ C ) = (/) ) <-> ( D i^i E ) = (/) ) ) |
60 |
40 59
|
anbi12d |
|- ( ( A e. V /\ B e. V /\ A =/= B ) -> ( ( A. z e. { A , B } ( A = z \/ ( D i^i [_ z / x ]_ C ) = (/) ) /\ A. z e. { A , B } ( B = z \/ ( E i^i [_ z / x ]_ C ) = (/) ) ) <-> ( ( D i^i E ) = (/) /\ ( D i^i E ) = (/) ) ) ) |
61 |
20 60
|
bitrd |
|- ( ( A e. V /\ B e. V /\ A =/= B ) -> ( A. y e. { A , B } A. z e. { A , B } ( y = z \/ ( [_ y / x ]_ C i^i [_ z / x ]_ C ) = (/) ) <-> ( ( D i^i E ) = (/) /\ ( D i^i E ) = (/) ) ) ) |
62 |
|
disjors |
|- ( Disj_ x e. { A , B } C <-> A. y e. { A , B } A. z e. { A , B } ( y = z \/ ( [_ y / x ]_ C i^i [_ z / x ]_ C ) = (/) ) ) |
63 |
|
pm4.24 |
|- ( ( D i^i E ) = (/) <-> ( ( D i^i E ) = (/) /\ ( D i^i E ) = (/) ) ) |
64 |
61 62 63
|
3bitr4g |
|- ( ( A e. V /\ B e. V /\ A =/= B ) -> ( Disj_ x e. { A , B } C <-> ( D i^i E ) = (/) ) ) |