| Step |
Hyp |
Ref |
Expression |
| 1 |
|
vex |
|- x e. _V |
| 2 |
|
vex |
|- y e. _V |
| 3 |
1 2
|
pm3.2i |
|- ( x e. _V /\ y e. _V ) |
| 4 |
3
|
a1i |
|- ( ph -> ( x e. _V /\ y e. _V ) ) |
| 5 |
4
|
ssopab2i |
|- { <. x , y >. | ph } C_ { <. x , y >. | ( x e. _V /\ y e. _V ) } |
| 6 |
3
|
biantru |
|- ( z = <. x , y >. <-> ( z = <. x , y >. /\ ( x e. _V /\ y e. _V ) ) ) |
| 7 |
6
|
exbii |
|- ( E. y z = <. x , y >. <-> E. y ( z = <. x , y >. /\ ( x e. _V /\ y e. _V ) ) ) |
| 8 |
7
|
exbii |
|- ( E. x E. y z = <. x , y >. <-> E. x E. y ( z = <. x , y >. /\ ( x e. _V /\ y e. _V ) ) ) |
| 9 |
8
|
abbii |
|- { z | E. x E. y z = <. x , y >. } = { z | E. x E. y ( z = <. x , y >. /\ ( x e. _V /\ y e. _V ) ) } |
| 10 |
|
ax6ev |
|- E. u u = x |
| 11 |
|
equcom |
|- ( u = x <-> x = u ) |
| 12 |
11
|
exbii |
|- ( E. u u = x <-> E. u x = u ) |
| 13 |
10 12
|
mpbi |
|- E. u x = u |
| 14 |
|
ax6ev |
|- E. v v = y |
| 15 |
|
equcom |
|- ( v = y <-> y = v ) |
| 16 |
15
|
exbii |
|- ( E. v v = y <-> E. v y = v ) |
| 17 |
14 16
|
mpbi |
|- E. v y = v |
| 18 |
|
idn1 |
|- (. y = v ->. y = v ). |
| 19 |
|
opeq2 |
|- ( y = v -> <. x , y >. = <. x , v >. ) |
| 20 |
18 19
|
e1a |
|- (. y = v ->. <. x , y >. = <. x , v >. ). |
| 21 |
|
idn2 |
|- (. y = v ,. x = u ->. x = u ). |
| 22 |
|
opeq1 |
|- ( x = u -> <. x , v >. = <. u , v >. ) |
| 23 |
21 22
|
e2 |
|- (. y = v ,. x = u ->. <. x , v >. = <. u , v >. ). |
| 24 |
|
eqeq1 |
|- ( <. x , y >. = <. x , v >. -> ( <. x , y >. = <. u , v >. <-> <. x , v >. = <. u , v >. ) ) |
| 25 |
24
|
biimprd |
|- ( <. x , y >. = <. x , v >. -> ( <. x , v >. = <. u , v >. -> <. x , y >. = <. u , v >. ) ) |
| 26 |
20 23 25
|
e12 |
|- (. y = v ,. x = u ->. <. x , y >. = <. u , v >. ). |
| 27 |
|
eqeq2 |
|- ( <. x , y >. = <. u , v >. -> ( z = <. x , y >. <-> z = <. u , v >. ) ) |
| 28 |
27
|
biimpd |
|- ( <. x , y >. = <. u , v >. -> ( z = <. x , y >. -> z = <. u , v >. ) ) |
| 29 |
26 28
|
e2 |
|- (. y = v ,. x = u ->. ( z = <. x , y >. -> z = <. u , v >. ) ). |
| 30 |
29
|
in2 |
|- (. y = v ->. ( x = u -> ( z = <. x , y >. -> z = <. u , v >. ) ) ). |
| 31 |
30
|
in1 |
|- ( y = v -> ( x = u -> ( z = <. x , y >. -> z = <. u , v >. ) ) ) |
| 32 |
31
|
eximi |
|- ( E. v y = v -> E. v ( x = u -> ( z = <. x , y >. -> z = <. u , v >. ) ) ) |
| 33 |
17 32
|
ax-mp |
|- E. v ( x = u -> ( z = <. x , y >. -> z = <. u , v >. ) ) |
| 34 |
33
|
19.37iv |
|- ( x = u -> E. v ( z = <. x , y >. -> z = <. u , v >. ) ) |
| 35 |
|
19.37v |
|- ( E. v ( z = <. x , y >. -> z = <. u , v >. ) <-> ( z = <. x , y >. -> E. v z = <. u , v >. ) ) |
| 36 |
35
|
biimpi |
|- ( E. v ( z = <. x , y >. -> z = <. u , v >. ) -> ( z = <. x , y >. -> E. v z = <. u , v >. ) ) |
| 37 |
34 36
|
syl |
|- ( x = u -> ( z = <. x , y >. -> E. v z = <. u , v >. ) ) |
| 38 |
37
|
eximi |
|- ( E. u x = u -> E. u ( z = <. x , y >. -> E. v z = <. u , v >. ) ) |
| 39 |
13 38
|
ax-mp |
|- E. u ( z = <. x , y >. -> E. v z = <. u , v >. ) |
| 40 |
39
|
19.37iv |
|- ( z = <. x , y >. -> E. u E. v z = <. u , v >. ) |
| 41 |
40
|
eximi |
|- ( E. y z = <. x , y >. -> E. y E. u E. v z = <. u , v >. ) |
| 42 |
|
19.9v |
|- ( E. y E. u E. v z = <. u , v >. <-> E. u E. v z = <. u , v >. ) |
| 43 |
42
|
biimpi |
|- ( E. y E. u E. v z = <. u , v >. -> E. u E. v z = <. u , v >. ) |
| 44 |
41 43
|
syl |
|- ( E. y z = <. x , y >. -> E. u E. v z = <. u , v >. ) |
| 45 |
44
|
eximi |
|- ( E. x E. y z = <. x , y >. -> E. x E. u E. v z = <. u , v >. ) |
| 46 |
|
19.9v |
|- ( E. x E. u E. v z = <. u , v >. <-> E. u E. v z = <. u , v >. ) |
| 47 |
46
|
biimpi |
|- ( E. x E. u E. v z = <. u , v >. -> E. u E. v z = <. u , v >. ) |
| 48 |
45 47
|
syl |
|- ( E. x E. y z = <. x , y >. -> E. u E. v z = <. u , v >. ) |
| 49 |
48
|
ss2abi |
|- { z | E. x E. y z = <. x , y >. } C_ { z | E. u E. v z = <. u , v >. } |
| 50 |
9 49
|
eqsstrri |
|- { z | E. x E. y ( z = <. x , y >. /\ ( x e. _V /\ y e. _V ) ) } C_ { z | E. u E. v z = <. u , v >. } |
| 51 |
|
vex |
|- u e. _V |
| 52 |
|
vex |
|- v e. _V |
| 53 |
51 52
|
pm3.2i |
|- ( u e. _V /\ v e. _V ) |
| 54 |
53
|
biantru |
|- ( z = <. u , v >. <-> ( z = <. u , v >. /\ ( u e. _V /\ v e. _V ) ) ) |
| 55 |
54
|
exbii |
|- ( E. v z = <. u , v >. <-> E. v ( z = <. u , v >. /\ ( u e. _V /\ v e. _V ) ) ) |
| 56 |
55
|
exbii |
|- ( E. u E. v z = <. u , v >. <-> E. u E. v ( z = <. u , v >. /\ ( u e. _V /\ v e. _V ) ) ) |
| 57 |
56
|
abbii |
|- { z | E. u E. v z = <. u , v >. } = { z | E. u E. v ( z = <. u , v >. /\ ( u e. _V /\ v e. _V ) ) } |
| 58 |
50 57
|
sseqtri |
|- { z | E. x E. y ( z = <. x , y >. /\ ( x e. _V /\ y e. _V ) ) } C_ { z | E. u E. v ( z = <. u , v >. /\ ( u e. _V /\ v e. _V ) ) } |
| 59 |
|
df-opab |
|- { <. x , y >. | ( x e. _V /\ y e. _V ) } = { z | E. x E. y ( z = <. x , y >. /\ ( x e. _V /\ y e. _V ) ) } |
| 60 |
|
df-opab |
|- { <. u , v >. | ( u e. _V /\ v e. _V ) } = { z | E. u E. v ( z = <. u , v >. /\ ( u e. _V /\ v e. _V ) ) } |
| 61 |
58 59 60
|
3sstr4i |
|- { <. x , y >. | ( x e. _V /\ y e. _V ) } C_ { <. u , v >. | ( u e. _V /\ v e. _V ) } |
| 62 |
|
df-xp |
|- ( _V X. _V ) = { <. u , v >. | ( u e. _V /\ v e. _V ) } |
| 63 |
62
|
eqcomi |
|- { <. u , v >. | ( u e. _V /\ v e. _V ) } = ( _V X. _V ) |
| 64 |
61 63
|
sseqtri |
|- { <. x , y >. | ( x e. _V /\ y e. _V ) } C_ ( _V X. _V ) |
| 65 |
5 64
|
sstri |
|- { <. x , y >. | ph } C_ ( _V X. _V ) |
| 66 |
|
df-rel |
|- ( Rel { <. x , y >. | ph } <-> { <. x , y >. | ph } C_ ( _V X. _V ) ) |
| 67 |
66
|
biimpri |
|- ( { <. x , y >. | ph } C_ ( _V X. _V ) -> Rel { <. x , y >. | ph } ) |
| 68 |
65 67
|
e0a |
|- Rel { <. x , y >. | ph } |