Step |
Hyp |
Ref |
Expression |
1 |
|
sprval |
⊢ ( 𝑉 ∈ V → ( Pairs ‘ 𝑉 ) = { 𝑝 ∣ ∃ 𝑎 ∈ 𝑉 ∃ 𝑏 ∈ 𝑉 𝑝 = { 𝑎 , 𝑏 } } ) |
2 |
1
|
abeq2d |
⊢ ( 𝑉 ∈ V → ( 𝑝 ∈ ( Pairs ‘ 𝑉 ) ↔ ∃ 𝑎 ∈ 𝑉 ∃ 𝑏 ∈ 𝑉 𝑝 = { 𝑎 , 𝑏 } ) ) |
3 |
2
|
anbi1d |
⊢ ( 𝑉 ∈ V → ( ( 𝑝 ∈ ( Pairs ‘ 𝑉 ) ∧ ( ♯ ‘ 𝑝 ) = 2 ) ↔ ( ∃ 𝑎 ∈ 𝑉 ∃ 𝑏 ∈ 𝑉 𝑝 = { 𝑎 , 𝑏 } ∧ ( ♯ ‘ 𝑝 ) = 2 ) ) ) |
4 |
|
r19.41vv |
⊢ ( ∃ 𝑎 ∈ 𝑉 ∃ 𝑏 ∈ 𝑉 ( 𝑝 = { 𝑎 , 𝑏 } ∧ ( ♯ ‘ 𝑝 ) = 2 ) ↔ ( ∃ 𝑎 ∈ 𝑉 ∃ 𝑏 ∈ 𝑉 𝑝 = { 𝑎 , 𝑏 } ∧ ( ♯ ‘ 𝑝 ) = 2 ) ) |
5 |
|
fveqeq2 |
⊢ ( 𝑝 = { 𝑎 , 𝑏 } → ( ( ♯ ‘ 𝑝 ) = 2 ↔ ( ♯ ‘ { 𝑎 , 𝑏 } ) = 2 ) ) |
6 |
|
hashprg |
⊢ ( ( 𝑎 ∈ V ∧ 𝑏 ∈ V ) → ( 𝑎 ≠ 𝑏 ↔ ( ♯ ‘ { 𝑎 , 𝑏 } ) = 2 ) ) |
7 |
6
|
el2v |
⊢ ( 𝑎 ≠ 𝑏 ↔ ( ♯ ‘ { 𝑎 , 𝑏 } ) = 2 ) |
8 |
5 7
|
bitr4di |
⊢ ( 𝑝 = { 𝑎 , 𝑏 } → ( ( ♯ ‘ 𝑝 ) = 2 ↔ 𝑎 ≠ 𝑏 ) ) |
9 |
8
|
pm5.32i |
⊢ ( ( 𝑝 = { 𝑎 , 𝑏 } ∧ ( ♯ ‘ 𝑝 ) = 2 ) ↔ ( 𝑝 = { 𝑎 , 𝑏 } ∧ 𝑎 ≠ 𝑏 ) ) |
10 |
9
|
biancomi |
⊢ ( ( 𝑝 = { 𝑎 , 𝑏 } ∧ ( ♯ ‘ 𝑝 ) = 2 ) ↔ ( 𝑎 ≠ 𝑏 ∧ 𝑝 = { 𝑎 , 𝑏 } ) ) |
11 |
10
|
a1i |
⊢ ( ( 𝑉 ∈ V ∧ ( 𝑎 ∈ 𝑉 ∧ 𝑏 ∈ 𝑉 ) ) → ( ( 𝑝 = { 𝑎 , 𝑏 } ∧ ( ♯ ‘ 𝑝 ) = 2 ) ↔ ( 𝑎 ≠ 𝑏 ∧ 𝑝 = { 𝑎 , 𝑏 } ) ) ) |
12 |
11
|
2rexbidva |
⊢ ( 𝑉 ∈ V → ( ∃ 𝑎 ∈ 𝑉 ∃ 𝑏 ∈ 𝑉 ( 𝑝 = { 𝑎 , 𝑏 } ∧ ( ♯ ‘ 𝑝 ) = 2 ) ↔ ∃ 𝑎 ∈ 𝑉 ∃ 𝑏 ∈ 𝑉 ( 𝑎 ≠ 𝑏 ∧ 𝑝 = { 𝑎 , 𝑏 } ) ) ) |
13 |
4 12
|
bitr3id |
⊢ ( 𝑉 ∈ V → ( ( ∃ 𝑎 ∈ 𝑉 ∃ 𝑏 ∈ 𝑉 𝑝 = { 𝑎 , 𝑏 } ∧ ( ♯ ‘ 𝑝 ) = 2 ) ↔ ∃ 𝑎 ∈ 𝑉 ∃ 𝑏 ∈ 𝑉 ( 𝑎 ≠ 𝑏 ∧ 𝑝 = { 𝑎 , 𝑏 } ) ) ) |
14 |
3 13
|
bitrd |
⊢ ( 𝑉 ∈ V → ( ( 𝑝 ∈ ( Pairs ‘ 𝑉 ) ∧ ( ♯ ‘ 𝑝 ) = 2 ) ↔ ∃ 𝑎 ∈ 𝑉 ∃ 𝑏 ∈ 𝑉 ( 𝑎 ≠ 𝑏 ∧ 𝑝 = { 𝑎 , 𝑏 } ) ) ) |
15 |
14
|
abbidv |
⊢ ( 𝑉 ∈ V → { 𝑝 ∣ ( 𝑝 ∈ ( Pairs ‘ 𝑉 ) ∧ ( ♯ ‘ 𝑝 ) = 2 ) } = { 𝑝 ∣ ∃ 𝑎 ∈ 𝑉 ∃ 𝑏 ∈ 𝑉 ( 𝑎 ≠ 𝑏 ∧ 𝑝 = { 𝑎 , 𝑏 } ) } ) |
16 |
|
df-rab |
⊢ { 𝑝 ∈ ( Pairs ‘ 𝑉 ) ∣ ( ♯ ‘ 𝑝 ) = 2 } = { 𝑝 ∣ ( 𝑝 ∈ ( Pairs ‘ 𝑉 ) ∧ ( ♯ ‘ 𝑝 ) = 2 ) } |
17 |
16
|
a1i |
⊢ ( 𝑉 ∈ V → { 𝑝 ∈ ( Pairs ‘ 𝑉 ) ∣ ( ♯ ‘ 𝑝 ) = 2 } = { 𝑝 ∣ ( 𝑝 ∈ ( Pairs ‘ 𝑉 ) ∧ ( ♯ ‘ 𝑝 ) = 2 ) } ) |
18 |
|
prprval |
⊢ ( 𝑉 ∈ V → ( Pairsproper ‘ 𝑉 ) = { 𝑝 ∣ ∃ 𝑎 ∈ 𝑉 ∃ 𝑏 ∈ 𝑉 ( 𝑎 ≠ 𝑏 ∧ 𝑝 = { 𝑎 , 𝑏 } ) } ) |
19 |
15 17 18
|
3eqtr4rd |
⊢ ( 𝑉 ∈ V → ( Pairsproper ‘ 𝑉 ) = { 𝑝 ∈ ( Pairs ‘ 𝑉 ) ∣ ( ♯ ‘ 𝑝 ) = 2 } ) |
20 |
|
rab0 |
⊢ { 𝑝 ∈ ∅ ∣ ( ♯ ‘ 𝑝 ) = 2 } = ∅ |
21 |
20
|
a1i |
⊢ ( ¬ 𝑉 ∈ V → { 𝑝 ∈ ∅ ∣ ( ♯ ‘ 𝑝 ) = 2 } = ∅ ) |
22 |
|
fvprc |
⊢ ( ¬ 𝑉 ∈ V → ( Pairs ‘ 𝑉 ) = ∅ ) |
23 |
22
|
rabeqdv |
⊢ ( ¬ 𝑉 ∈ V → { 𝑝 ∈ ( Pairs ‘ 𝑉 ) ∣ ( ♯ ‘ 𝑝 ) = 2 } = { 𝑝 ∈ ∅ ∣ ( ♯ ‘ 𝑝 ) = 2 } ) |
24 |
|
fvprc |
⊢ ( ¬ 𝑉 ∈ V → ( Pairsproper ‘ 𝑉 ) = ∅ ) |
25 |
21 23 24
|
3eqtr4rd |
⊢ ( ¬ 𝑉 ∈ V → ( Pairsproper ‘ 𝑉 ) = { 𝑝 ∈ ( Pairs ‘ 𝑉 ) ∣ ( ♯ ‘ 𝑝 ) = 2 } ) |
26 |
19 25
|
pm2.61i |
⊢ ( Pairsproper ‘ 𝑉 ) = { 𝑝 ∈ ( Pairs ‘ 𝑉 ) ∣ ( ♯ ‘ 𝑝 ) = 2 } |