Step |
Hyp |
Ref |
Expression |
1 |
|
idn1 |
⊢ ( 𝐴 ∈ 𝑉 ▶ 𝐴 ∈ 𝑉 ) |
2 |
|
sbcg |
⊢ ( 𝐴 ∈ 𝑉 → ( [ 𝐴 / 𝑥 ] 𝑧 ∈ 𝑦 ↔ 𝑧 ∈ 𝑦 ) ) |
3 |
1 2
|
e1a |
⊢ ( 𝐴 ∈ 𝑉 ▶ ( [ 𝐴 / 𝑥 ] 𝑧 ∈ 𝑦 ↔ 𝑧 ∈ 𝑦 ) ) |
4 |
|
sbcel2 |
⊢ ( [ 𝐴 / 𝑥 ] 𝑦 ∈ 𝐵 ↔ 𝑦 ∈ ⦋ 𝐴 / 𝑥 ⦌ 𝐵 ) |
5 |
4
|
a1i |
⊢ ( 𝐴 ∈ 𝑉 → ( [ 𝐴 / 𝑥 ] 𝑦 ∈ 𝐵 ↔ 𝑦 ∈ ⦋ 𝐴 / 𝑥 ⦌ 𝐵 ) ) |
6 |
1 5
|
e1a |
⊢ ( 𝐴 ∈ 𝑉 ▶ ( [ 𝐴 / 𝑥 ] 𝑦 ∈ 𝐵 ↔ 𝑦 ∈ ⦋ 𝐴 / 𝑥 ⦌ 𝐵 ) ) |
7 |
|
pm4.38 |
⊢ ( ( ( [ 𝐴 / 𝑥 ] 𝑧 ∈ 𝑦 ↔ 𝑧 ∈ 𝑦 ) ∧ ( [ 𝐴 / 𝑥 ] 𝑦 ∈ 𝐵 ↔ 𝑦 ∈ ⦋ 𝐴 / 𝑥 ⦌ 𝐵 ) ) → ( ( [ 𝐴 / 𝑥 ] 𝑧 ∈ 𝑦 ∧ [ 𝐴 / 𝑥 ] 𝑦 ∈ 𝐵 ) ↔ ( 𝑧 ∈ 𝑦 ∧ 𝑦 ∈ ⦋ 𝐴 / 𝑥 ⦌ 𝐵 ) ) ) |
8 |
7
|
ex |
⊢ ( ( [ 𝐴 / 𝑥 ] 𝑧 ∈ 𝑦 ↔ 𝑧 ∈ 𝑦 ) → ( ( [ 𝐴 / 𝑥 ] 𝑦 ∈ 𝐵 ↔ 𝑦 ∈ ⦋ 𝐴 / 𝑥 ⦌ 𝐵 ) → ( ( [ 𝐴 / 𝑥 ] 𝑧 ∈ 𝑦 ∧ [ 𝐴 / 𝑥 ] 𝑦 ∈ 𝐵 ) ↔ ( 𝑧 ∈ 𝑦 ∧ 𝑦 ∈ ⦋ 𝐴 / 𝑥 ⦌ 𝐵 ) ) ) ) |
9 |
3 6 8
|
e11 |
⊢ ( 𝐴 ∈ 𝑉 ▶ ( ( [ 𝐴 / 𝑥 ] 𝑧 ∈ 𝑦 ∧ [ 𝐴 / 𝑥 ] 𝑦 ∈ 𝐵 ) ↔ ( 𝑧 ∈ 𝑦 ∧ 𝑦 ∈ ⦋ 𝐴 / 𝑥 ⦌ 𝐵 ) ) ) |
10 |
|
sbcan |
⊢ ( [ 𝐴 / 𝑥 ] ( 𝑧 ∈ 𝑦 ∧ 𝑦 ∈ 𝐵 ) ↔ ( [ 𝐴 / 𝑥 ] 𝑧 ∈ 𝑦 ∧ [ 𝐴 / 𝑥 ] 𝑦 ∈ 𝐵 ) ) |
11 |
10
|
a1i |
⊢ ( 𝐴 ∈ 𝑉 → ( [ 𝐴 / 𝑥 ] ( 𝑧 ∈ 𝑦 ∧ 𝑦 ∈ 𝐵 ) ↔ ( [ 𝐴 / 𝑥 ] 𝑧 ∈ 𝑦 ∧ [ 𝐴 / 𝑥 ] 𝑦 ∈ 𝐵 ) ) ) |
12 |
1 11
|
e1a |
⊢ ( 𝐴 ∈ 𝑉 ▶ ( [ 𝐴 / 𝑥 ] ( 𝑧 ∈ 𝑦 ∧ 𝑦 ∈ 𝐵 ) ↔ ( [ 𝐴 / 𝑥 ] 𝑧 ∈ 𝑦 ∧ [ 𝐴 / 𝑥 ] 𝑦 ∈ 𝐵 ) ) ) |
13 |
|
bibi1 |
⊢ ( ( [ 𝐴 / 𝑥 ] ( 𝑧 ∈ 𝑦 ∧ 𝑦 ∈ 𝐵 ) ↔ ( [ 𝐴 / 𝑥 ] 𝑧 ∈ 𝑦 ∧ [ 𝐴 / 𝑥 ] 𝑦 ∈ 𝐵 ) ) → ( ( [ 𝐴 / 𝑥 ] ( 𝑧 ∈ 𝑦 ∧ 𝑦 ∈ 𝐵 ) ↔ ( 𝑧 ∈ 𝑦 ∧ 𝑦 ∈ ⦋ 𝐴 / 𝑥 ⦌ 𝐵 ) ) ↔ ( ( [ 𝐴 / 𝑥 ] 𝑧 ∈ 𝑦 ∧ [ 𝐴 / 𝑥 ] 𝑦 ∈ 𝐵 ) ↔ ( 𝑧 ∈ 𝑦 ∧ 𝑦 ∈ ⦋ 𝐴 / 𝑥 ⦌ 𝐵 ) ) ) ) |
14 |
13
|
biimprcd |
⊢ ( ( ( [ 𝐴 / 𝑥 ] 𝑧 ∈ 𝑦 ∧ [ 𝐴 / 𝑥 ] 𝑦 ∈ 𝐵 ) ↔ ( 𝑧 ∈ 𝑦 ∧ 𝑦 ∈ ⦋ 𝐴 / 𝑥 ⦌ 𝐵 ) ) → ( ( [ 𝐴 / 𝑥 ] ( 𝑧 ∈ 𝑦 ∧ 𝑦 ∈ 𝐵 ) ↔ ( [ 𝐴 / 𝑥 ] 𝑧 ∈ 𝑦 ∧ [ 𝐴 / 𝑥 ] 𝑦 ∈ 𝐵 ) ) → ( [ 𝐴 / 𝑥 ] ( 𝑧 ∈ 𝑦 ∧ 𝑦 ∈ 𝐵 ) ↔ ( 𝑧 ∈ 𝑦 ∧ 𝑦 ∈ ⦋ 𝐴 / 𝑥 ⦌ 𝐵 ) ) ) ) |
15 |
9 12 14
|
e11 |
⊢ ( 𝐴 ∈ 𝑉 ▶ ( [ 𝐴 / 𝑥 ] ( 𝑧 ∈ 𝑦 ∧ 𝑦 ∈ 𝐵 ) ↔ ( 𝑧 ∈ 𝑦 ∧ 𝑦 ∈ ⦋ 𝐴 / 𝑥 ⦌ 𝐵 ) ) ) |
16 |
15
|
gen11 |
⊢ ( 𝐴 ∈ 𝑉 ▶ ∀ 𝑦 ( [ 𝐴 / 𝑥 ] ( 𝑧 ∈ 𝑦 ∧ 𝑦 ∈ 𝐵 ) ↔ ( 𝑧 ∈ 𝑦 ∧ 𝑦 ∈ ⦋ 𝐴 / 𝑥 ⦌ 𝐵 ) ) ) |
17 |
|
exbi |
⊢ ( ∀ 𝑦 ( [ 𝐴 / 𝑥 ] ( 𝑧 ∈ 𝑦 ∧ 𝑦 ∈ 𝐵 ) ↔ ( 𝑧 ∈ 𝑦 ∧ 𝑦 ∈ ⦋ 𝐴 / 𝑥 ⦌ 𝐵 ) ) → ( ∃ 𝑦 [ 𝐴 / 𝑥 ] ( 𝑧 ∈ 𝑦 ∧ 𝑦 ∈ 𝐵 ) ↔ ∃ 𝑦 ( 𝑧 ∈ 𝑦 ∧ 𝑦 ∈ ⦋ 𝐴 / 𝑥 ⦌ 𝐵 ) ) ) |
18 |
16 17
|
e1a |
⊢ ( 𝐴 ∈ 𝑉 ▶ ( ∃ 𝑦 [ 𝐴 / 𝑥 ] ( 𝑧 ∈ 𝑦 ∧ 𝑦 ∈ 𝐵 ) ↔ ∃ 𝑦 ( 𝑧 ∈ 𝑦 ∧ 𝑦 ∈ ⦋ 𝐴 / 𝑥 ⦌ 𝐵 ) ) ) |
19 |
|
sbcex2 |
⊢ ( [ 𝐴 / 𝑥 ] ∃ 𝑦 ( 𝑧 ∈ 𝑦 ∧ 𝑦 ∈ 𝐵 ) ↔ ∃ 𝑦 [ 𝐴 / 𝑥 ] ( 𝑧 ∈ 𝑦 ∧ 𝑦 ∈ 𝐵 ) ) |
20 |
19
|
a1i |
⊢ ( 𝐴 ∈ 𝑉 → ( [ 𝐴 / 𝑥 ] ∃ 𝑦 ( 𝑧 ∈ 𝑦 ∧ 𝑦 ∈ 𝐵 ) ↔ ∃ 𝑦 [ 𝐴 / 𝑥 ] ( 𝑧 ∈ 𝑦 ∧ 𝑦 ∈ 𝐵 ) ) ) |
21 |
1 20
|
e1a |
⊢ ( 𝐴 ∈ 𝑉 ▶ ( [ 𝐴 / 𝑥 ] ∃ 𝑦 ( 𝑧 ∈ 𝑦 ∧ 𝑦 ∈ 𝐵 ) ↔ ∃ 𝑦 [ 𝐴 / 𝑥 ] ( 𝑧 ∈ 𝑦 ∧ 𝑦 ∈ 𝐵 ) ) ) |
22 |
|
bibi1 |
⊢ ( ( [ 𝐴 / 𝑥 ] ∃ 𝑦 ( 𝑧 ∈ 𝑦 ∧ 𝑦 ∈ 𝐵 ) ↔ ∃ 𝑦 [ 𝐴 / 𝑥 ] ( 𝑧 ∈ 𝑦 ∧ 𝑦 ∈ 𝐵 ) ) → ( ( [ 𝐴 / 𝑥 ] ∃ 𝑦 ( 𝑧 ∈ 𝑦 ∧ 𝑦 ∈ 𝐵 ) ↔ ∃ 𝑦 ( 𝑧 ∈ 𝑦 ∧ 𝑦 ∈ ⦋ 𝐴 / 𝑥 ⦌ 𝐵 ) ) ↔ ( ∃ 𝑦 [ 𝐴 / 𝑥 ] ( 𝑧 ∈ 𝑦 ∧ 𝑦 ∈ 𝐵 ) ↔ ∃ 𝑦 ( 𝑧 ∈ 𝑦 ∧ 𝑦 ∈ ⦋ 𝐴 / 𝑥 ⦌ 𝐵 ) ) ) ) |
23 |
22
|
biimprcd |
⊢ ( ( ∃ 𝑦 [ 𝐴 / 𝑥 ] ( 𝑧 ∈ 𝑦 ∧ 𝑦 ∈ 𝐵 ) ↔ ∃ 𝑦 ( 𝑧 ∈ 𝑦 ∧ 𝑦 ∈ ⦋ 𝐴 / 𝑥 ⦌ 𝐵 ) ) → ( ( [ 𝐴 / 𝑥 ] ∃ 𝑦 ( 𝑧 ∈ 𝑦 ∧ 𝑦 ∈ 𝐵 ) ↔ ∃ 𝑦 [ 𝐴 / 𝑥 ] ( 𝑧 ∈ 𝑦 ∧ 𝑦 ∈ 𝐵 ) ) → ( [ 𝐴 / 𝑥 ] ∃ 𝑦 ( 𝑧 ∈ 𝑦 ∧ 𝑦 ∈ 𝐵 ) ↔ ∃ 𝑦 ( 𝑧 ∈ 𝑦 ∧ 𝑦 ∈ ⦋ 𝐴 / 𝑥 ⦌ 𝐵 ) ) ) ) |
24 |
18 21 23
|
e11 |
⊢ ( 𝐴 ∈ 𝑉 ▶ ( [ 𝐴 / 𝑥 ] ∃ 𝑦 ( 𝑧 ∈ 𝑦 ∧ 𝑦 ∈ 𝐵 ) ↔ ∃ 𝑦 ( 𝑧 ∈ 𝑦 ∧ 𝑦 ∈ ⦋ 𝐴 / 𝑥 ⦌ 𝐵 ) ) ) |
25 |
24
|
gen11 |
⊢ ( 𝐴 ∈ 𝑉 ▶ ∀ 𝑧 ( [ 𝐴 / 𝑥 ] ∃ 𝑦 ( 𝑧 ∈ 𝑦 ∧ 𝑦 ∈ 𝐵 ) ↔ ∃ 𝑦 ( 𝑧 ∈ 𝑦 ∧ 𝑦 ∈ ⦋ 𝐴 / 𝑥 ⦌ 𝐵 ) ) ) |
26 |
|
abbi |
⊢ ( ∀ 𝑧 ( [ 𝐴 / 𝑥 ] ∃ 𝑦 ( 𝑧 ∈ 𝑦 ∧ 𝑦 ∈ 𝐵 ) ↔ ∃ 𝑦 ( 𝑧 ∈ 𝑦 ∧ 𝑦 ∈ ⦋ 𝐴 / 𝑥 ⦌ 𝐵 ) ) ↔ { 𝑧 ∣ [ 𝐴 / 𝑥 ] ∃ 𝑦 ( 𝑧 ∈ 𝑦 ∧ 𝑦 ∈ 𝐵 ) } = { 𝑧 ∣ ∃ 𝑦 ( 𝑧 ∈ 𝑦 ∧ 𝑦 ∈ ⦋ 𝐴 / 𝑥 ⦌ 𝐵 ) } ) |
27 |
26
|
biimpi |
⊢ ( ∀ 𝑧 ( [ 𝐴 / 𝑥 ] ∃ 𝑦 ( 𝑧 ∈ 𝑦 ∧ 𝑦 ∈ 𝐵 ) ↔ ∃ 𝑦 ( 𝑧 ∈ 𝑦 ∧ 𝑦 ∈ ⦋ 𝐴 / 𝑥 ⦌ 𝐵 ) ) → { 𝑧 ∣ [ 𝐴 / 𝑥 ] ∃ 𝑦 ( 𝑧 ∈ 𝑦 ∧ 𝑦 ∈ 𝐵 ) } = { 𝑧 ∣ ∃ 𝑦 ( 𝑧 ∈ 𝑦 ∧ 𝑦 ∈ ⦋ 𝐴 / 𝑥 ⦌ 𝐵 ) } ) |
28 |
25 27
|
e1a |
⊢ ( 𝐴 ∈ 𝑉 ▶ { 𝑧 ∣ [ 𝐴 / 𝑥 ] ∃ 𝑦 ( 𝑧 ∈ 𝑦 ∧ 𝑦 ∈ 𝐵 ) } = { 𝑧 ∣ ∃ 𝑦 ( 𝑧 ∈ 𝑦 ∧ 𝑦 ∈ ⦋ 𝐴 / 𝑥 ⦌ 𝐵 ) } ) |
29 |
|
csbab |
⊢ ⦋ 𝐴 / 𝑥 ⦌ { 𝑧 ∣ ∃ 𝑦 ( 𝑧 ∈ 𝑦 ∧ 𝑦 ∈ 𝐵 ) } = { 𝑧 ∣ [ 𝐴 / 𝑥 ] ∃ 𝑦 ( 𝑧 ∈ 𝑦 ∧ 𝑦 ∈ 𝐵 ) } |
30 |
29
|
a1i |
⊢ ( 𝐴 ∈ 𝑉 → ⦋ 𝐴 / 𝑥 ⦌ { 𝑧 ∣ ∃ 𝑦 ( 𝑧 ∈ 𝑦 ∧ 𝑦 ∈ 𝐵 ) } = { 𝑧 ∣ [ 𝐴 / 𝑥 ] ∃ 𝑦 ( 𝑧 ∈ 𝑦 ∧ 𝑦 ∈ 𝐵 ) } ) |
31 |
1 30
|
e1a |
⊢ ( 𝐴 ∈ 𝑉 ▶ ⦋ 𝐴 / 𝑥 ⦌ { 𝑧 ∣ ∃ 𝑦 ( 𝑧 ∈ 𝑦 ∧ 𝑦 ∈ 𝐵 ) } = { 𝑧 ∣ [ 𝐴 / 𝑥 ] ∃ 𝑦 ( 𝑧 ∈ 𝑦 ∧ 𝑦 ∈ 𝐵 ) } ) |
32 |
|
eqeq2 |
⊢ ( { 𝑧 ∣ [ 𝐴 / 𝑥 ] ∃ 𝑦 ( 𝑧 ∈ 𝑦 ∧ 𝑦 ∈ 𝐵 ) } = { 𝑧 ∣ ∃ 𝑦 ( 𝑧 ∈ 𝑦 ∧ 𝑦 ∈ ⦋ 𝐴 / 𝑥 ⦌ 𝐵 ) } → ( ⦋ 𝐴 / 𝑥 ⦌ { 𝑧 ∣ ∃ 𝑦 ( 𝑧 ∈ 𝑦 ∧ 𝑦 ∈ 𝐵 ) } = { 𝑧 ∣ [ 𝐴 / 𝑥 ] ∃ 𝑦 ( 𝑧 ∈ 𝑦 ∧ 𝑦 ∈ 𝐵 ) } ↔ ⦋ 𝐴 / 𝑥 ⦌ { 𝑧 ∣ ∃ 𝑦 ( 𝑧 ∈ 𝑦 ∧ 𝑦 ∈ 𝐵 ) } = { 𝑧 ∣ ∃ 𝑦 ( 𝑧 ∈ 𝑦 ∧ 𝑦 ∈ ⦋ 𝐴 / 𝑥 ⦌ 𝐵 ) } ) ) |
33 |
32
|
biimpd |
⊢ ( { 𝑧 ∣ [ 𝐴 / 𝑥 ] ∃ 𝑦 ( 𝑧 ∈ 𝑦 ∧ 𝑦 ∈ 𝐵 ) } = { 𝑧 ∣ ∃ 𝑦 ( 𝑧 ∈ 𝑦 ∧ 𝑦 ∈ ⦋ 𝐴 / 𝑥 ⦌ 𝐵 ) } → ( ⦋ 𝐴 / 𝑥 ⦌ { 𝑧 ∣ ∃ 𝑦 ( 𝑧 ∈ 𝑦 ∧ 𝑦 ∈ 𝐵 ) } = { 𝑧 ∣ [ 𝐴 / 𝑥 ] ∃ 𝑦 ( 𝑧 ∈ 𝑦 ∧ 𝑦 ∈ 𝐵 ) } → ⦋ 𝐴 / 𝑥 ⦌ { 𝑧 ∣ ∃ 𝑦 ( 𝑧 ∈ 𝑦 ∧ 𝑦 ∈ 𝐵 ) } = { 𝑧 ∣ ∃ 𝑦 ( 𝑧 ∈ 𝑦 ∧ 𝑦 ∈ ⦋ 𝐴 / 𝑥 ⦌ 𝐵 ) } ) ) |
34 |
28 31 33
|
e11 |
⊢ ( 𝐴 ∈ 𝑉 ▶ ⦋ 𝐴 / 𝑥 ⦌ { 𝑧 ∣ ∃ 𝑦 ( 𝑧 ∈ 𝑦 ∧ 𝑦 ∈ 𝐵 ) } = { 𝑧 ∣ ∃ 𝑦 ( 𝑧 ∈ 𝑦 ∧ 𝑦 ∈ ⦋ 𝐴 / 𝑥 ⦌ 𝐵 ) } ) |
35 |
|
df-uni |
⊢ ∪ 𝐵 = { 𝑧 ∣ ∃ 𝑦 ( 𝑧 ∈ 𝑦 ∧ 𝑦 ∈ 𝐵 ) } |
36 |
35
|
ax-gen |
⊢ ∀ 𝑥 ∪ 𝐵 = { 𝑧 ∣ ∃ 𝑦 ( 𝑧 ∈ 𝑦 ∧ 𝑦 ∈ 𝐵 ) } |
37 |
|
spsbc |
⊢ ( 𝐴 ∈ 𝑉 → ( ∀ 𝑥 ∪ 𝐵 = { 𝑧 ∣ ∃ 𝑦 ( 𝑧 ∈ 𝑦 ∧ 𝑦 ∈ 𝐵 ) } → [ 𝐴 / 𝑥 ] ∪ 𝐵 = { 𝑧 ∣ ∃ 𝑦 ( 𝑧 ∈ 𝑦 ∧ 𝑦 ∈ 𝐵 ) } ) ) |
38 |
1 36 37
|
e10 |
⊢ ( 𝐴 ∈ 𝑉 ▶ [ 𝐴 / 𝑥 ] ∪ 𝐵 = { 𝑧 ∣ ∃ 𝑦 ( 𝑧 ∈ 𝑦 ∧ 𝑦 ∈ 𝐵 ) } ) |
39 |
|
sbceqg |
⊢ ( 𝐴 ∈ 𝑉 → ( [ 𝐴 / 𝑥 ] ∪ 𝐵 = { 𝑧 ∣ ∃ 𝑦 ( 𝑧 ∈ 𝑦 ∧ 𝑦 ∈ 𝐵 ) } ↔ ⦋ 𝐴 / 𝑥 ⦌ ∪ 𝐵 = ⦋ 𝐴 / 𝑥 ⦌ { 𝑧 ∣ ∃ 𝑦 ( 𝑧 ∈ 𝑦 ∧ 𝑦 ∈ 𝐵 ) } ) ) |
40 |
39
|
biimpd |
⊢ ( 𝐴 ∈ 𝑉 → ( [ 𝐴 / 𝑥 ] ∪ 𝐵 = { 𝑧 ∣ ∃ 𝑦 ( 𝑧 ∈ 𝑦 ∧ 𝑦 ∈ 𝐵 ) } → ⦋ 𝐴 / 𝑥 ⦌ ∪ 𝐵 = ⦋ 𝐴 / 𝑥 ⦌ { 𝑧 ∣ ∃ 𝑦 ( 𝑧 ∈ 𝑦 ∧ 𝑦 ∈ 𝐵 ) } ) ) |
41 |
1 38 40
|
e11 |
⊢ ( 𝐴 ∈ 𝑉 ▶ ⦋ 𝐴 / 𝑥 ⦌ ∪ 𝐵 = ⦋ 𝐴 / 𝑥 ⦌ { 𝑧 ∣ ∃ 𝑦 ( 𝑧 ∈ 𝑦 ∧ 𝑦 ∈ 𝐵 ) } ) |
42 |
|
eqeq2 |
⊢ ( ⦋ 𝐴 / 𝑥 ⦌ { 𝑧 ∣ ∃ 𝑦 ( 𝑧 ∈ 𝑦 ∧ 𝑦 ∈ 𝐵 ) } = { 𝑧 ∣ ∃ 𝑦 ( 𝑧 ∈ 𝑦 ∧ 𝑦 ∈ ⦋ 𝐴 / 𝑥 ⦌ 𝐵 ) } → ( ⦋ 𝐴 / 𝑥 ⦌ ∪ 𝐵 = ⦋ 𝐴 / 𝑥 ⦌ { 𝑧 ∣ ∃ 𝑦 ( 𝑧 ∈ 𝑦 ∧ 𝑦 ∈ 𝐵 ) } ↔ ⦋ 𝐴 / 𝑥 ⦌ ∪ 𝐵 = { 𝑧 ∣ ∃ 𝑦 ( 𝑧 ∈ 𝑦 ∧ 𝑦 ∈ ⦋ 𝐴 / 𝑥 ⦌ 𝐵 ) } ) ) |
43 |
42
|
biimpd |
⊢ ( ⦋ 𝐴 / 𝑥 ⦌ { 𝑧 ∣ ∃ 𝑦 ( 𝑧 ∈ 𝑦 ∧ 𝑦 ∈ 𝐵 ) } = { 𝑧 ∣ ∃ 𝑦 ( 𝑧 ∈ 𝑦 ∧ 𝑦 ∈ ⦋ 𝐴 / 𝑥 ⦌ 𝐵 ) } → ( ⦋ 𝐴 / 𝑥 ⦌ ∪ 𝐵 = ⦋ 𝐴 / 𝑥 ⦌ { 𝑧 ∣ ∃ 𝑦 ( 𝑧 ∈ 𝑦 ∧ 𝑦 ∈ 𝐵 ) } → ⦋ 𝐴 / 𝑥 ⦌ ∪ 𝐵 = { 𝑧 ∣ ∃ 𝑦 ( 𝑧 ∈ 𝑦 ∧ 𝑦 ∈ ⦋ 𝐴 / 𝑥 ⦌ 𝐵 ) } ) ) |
44 |
34 41 43
|
e11 |
⊢ ( 𝐴 ∈ 𝑉 ▶ ⦋ 𝐴 / 𝑥 ⦌ ∪ 𝐵 = { 𝑧 ∣ ∃ 𝑦 ( 𝑧 ∈ 𝑦 ∧ 𝑦 ∈ ⦋ 𝐴 / 𝑥 ⦌ 𝐵 ) } ) |
45 |
|
df-uni |
⊢ ∪ ⦋ 𝐴 / 𝑥 ⦌ 𝐵 = { 𝑧 ∣ ∃ 𝑦 ( 𝑧 ∈ 𝑦 ∧ 𝑦 ∈ ⦋ 𝐴 / 𝑥 ⦌ 𝐵 ) } |
46 |
|
eqeq2 |
⊢ ( ∪ ⦋ 𝐴 / 𝑥 ⦌ 𝐵 = { 𝑧 ∣ ∃ 𝑦 ( 𝑧 ∈ 𝑦 ∧ 𝑦 ∈ ⦋ 𝐴 / 𝑥 ⦌ 𝐵 ) } → ( ⦋ 𝐴 / 𝑥 ⦌ ∪ 𝐵 = ∪ ⦋ 𝐴 / 𝑥 ⦌ 𝐵 ↔ ⦋ 𝐴 / 𝑥 ⦌ ∪ 𝐵 = { 𝑧 ∣ ∃ 𝑦 ( 𝑧 ∈ 𝑦 ∧ 𝑦 ∈ ⦋ 𝐴 / 𝑥 ⦌ 𝐵 ) } ) ) |
47 |
46
|
biimprcd |
⊢ ( ⦋ 𝐴 / 𝑥 ⦌ ∪ 𝐵 = { 𝑧 ∣ ∃ 𝑦 ( 𝑧 ∈ 𝑦 ∧ 𝑦 ∈ ⦋ 𝐴 / 𝑥 ⦌ 𝐵 ) } → ( ∪ ⦋ 𝐴 / 𝑥 ⦌ 𝐵 = { 𝑧 ∣ ∃ 𝑦 ( 𝑧 ∈ 𝑦 ∧ 𝑦 ∈ ⦋ 𝐴 / 𝑥 ⦌ 𝐵 ) } → ⦋ 𝐴 / 𝑥 ⦌ ∪ 𝐵 = ∪ ⦋ 𝐴 / 𝑥 ⦌ 𝐵 ) ) |
48 |
44 45 47
|
e10 |
⊢ ( 𝐴 ∈ 𝑉 ▶ ⦋ 𝐴 / 𝑥 ⦌ ∪ 𝐵 = ∪ ⦋ 𝐴 / 𝑥 ⦌ 𝐵 ) |
49 |
48
|
in1 |
⊢ ( 𝐴 ∈ 𝑉 → ⦋ 𝐴 / 𝑥 ⦌ ∪ 𝐵 = ∪ ⦋ 𝐴 / 𝑥 ⦌ 𝐵 ) |