| Step |
Hyp |
Ref |
Expression |
| 1 |
|
idn1 |
⊢ ( 𝐴 ∈ 𝐵 ▶ 𝐴 ∈ 𝐵 ) |
| 2 |
|
sbcel2 |
⊢ ( [ 𝐴 / 𝑥 ] 𝑦 ∈ 𝐶 ↔ 𝑦 ∈ ⦋ 𝐴 / 𝑥 ⦌ 𝐶 ) |
| 3 |
2
|
a1i |
⊢ ( 𝐴 ∈ 𝐵 → ( [ 𝐴 / 𝑥 ] 𝑦 ∈ 𝐶 ↔ 𝑦 ∈ ⦋ 𝐴 / 𝑥 ⦌ 𝐶 ) ) |
| 4 |
1 3
|
e1a |
⊢ ( 𝐴 ∈ 𝐵 ▶ ( [ 𝐴 / 𝑥 ] 𝑦 ∈ 𝐶 ↔ 𝑦 ∈ ⦋ 𝐴 / 𝑥 ⦌ 𝐶 ) ) |
| 5 |
|
sbcel2 |
⊢ ( [ 𝐴 / 𝑥 ] 𝑦 ∈ 𝐷 ↔ 𝑦 ∈ ⦋ 𝐴 / 𝑥 ⦌ 𝐷 ) |
| 6 |
5
|
a1i |
⊢ ( 𝐴 ∈ 𝐵 → ( [ 𝐴 / 𝑥 ] 𝑦 ∈ 𝐷 ↔ 𝑦 ∈ ⦋ 𝐴 / 𝑥 ⦌ 𝐷 ) ) |
| 7 |
1 6
|
e1a |
⊢ ( 𝐴 ∈ 𝐵 ▶ ( [ 𝐴 / 𝑥 ] 𝑦 ∈ 𝐷 ↔ 𝑦 ∈ ⦋ 𝐴 / 𝑥 ⦌ 𝐷 ) ) |
| 8 |
|
imbi12 |
⊢ ( ( [ 𝐴 / 𝑥 ] 𝑦 ∈ 𝐶 ↔ 𝑦 ∈ ⦋ 𝐴 / 𝑥 ⦌ 𝐶 ) → ( ( [ 𝐴 / 𝑥 ] 𝑦 ∈ 𝐷 ↔ 𝑦 ∈ ⦋ 𝐴 / 𝑥 ⦌ 𝐷 ) → ( ( [ 𝐴 / 𝑥 ] 𝑦 ∈ 𝐶 → [ 𝐴 / 𝑥 ] 𝑦 ∈ 𝐷 ) ↔ ( 𝑦 ∈ ⦋ 𝐴 / 𝑥 ⦌ 𝐶 → 𝑦 ∈ ⦋ 𝐴 / 𝑥 ⦌ 𝐷 ) ) ) ) |
| 9 |
4 7 8
|
e11 |
⊢ ( 𝐴 ∈ 𝐵 ▶ ( ( [ 𝐴 / 𝑥 ] 𝑦 ∈ 𝐶 → [ 𝐴 / 𝑥 ] 𝑦 ∈ 𝐷 ) ↔ ( 𝑦 ∈ ⦋ 𝐴 / 𝑥 ⦌ 𝐶 → 𝑦 ∈ ⦋ 𝐴 / 𝑥 ⦌ 𝐷 ) ) ) |
| 10 |
|
sbcimg |
⊢ ( 𝐴 ∈ 𝐵 → ( [ 𝐴 / 𝑥 ] ( 𝑦 ∈ 𝐶 → 𝑦 ∈ 𝐷 ) ↔ ( [ 𝐴 / 𝑥 ] 𝑦 ∈ 𝐶 → [ 𝐴 / 𝑥 ] 𝑦 ∈ 𝐷 ) ) ) |
| 11 |
1 10
|
e1a |
⊢ ( 𝐴 ∈ 𝐵 ▶ ( [ 𝐴 / 𝑥 ] ( 𝑦 ∈ 𝐶 → 𝑦 ∈ 𝐷 ) ↔ ( [ 𝐴 / 𝑥 ] 𝑦 ∈ 𝐶 → [ 𝐴 / 𝑥 ] 𝑦 ∈ 𝐷 ) ) ) |
| 12 |
|
bibi1 |
⊢ ( ( [ 𝐴 / 𝑥 ] ( 𝑦 ∈ 𝐶 → 𝑦 ∈ 𝐷 ) ↔ ( [ 𝐴 / 𝑥 ] 𝑦 ∈ 𝐶 → [ 𝐴 / 𝑥 ] 𝑦 ∈ 𝐷 ) ) → ( ( [ 𝐴 / 𝑥 ] ( 𝑦 ∈ 𝐶 → 𝑦 ∈ 𝐷 ) ↔ ( 𝑦 ∈ ⦋ 𝐴 / 𝑥 ⦌ 𝐶 → 𝑦 ∈ ⦋ 𝐴 / 𝑥 ⦌ 𝐷 ) ) ↔ ( ( [ 𝐴 / 𝑥 ] 𝑦 ∈ 𝐶 → [ 𝐴 / 𝑥 ] 𝑦 ∈ 𝐷 ) ↔ ( 𝑦 ∈ ⦋ 𝐴 / 𝑥 ⦌ 𝐶 → 𝑦 ∈ ⦋ 𝐴 / 𝑥 ⦌ 𝐷 ) ) ) ) |
| 13 |
12
|
biimprcd |
⊢ ( ( ( [ 𝐴 / 𝑥 ] 𝑦 ∈ 𝐶 → [ 𝐴 / 𝑥 ] 𝑦 ∈ 𝐷 ) ↔ ( 𝑦 ∈ ⦋ 𝐴 / 𝑥 ⦌ 𝐶 → 𝑦 ∈ ⦋ 𝐴 / 𝑥 ⦌ 𝐷 ) ) → ( ( [ 𝐴 / 𝑥 ] ( 𝑦 ∈ 𝐶 → 𝑦 ∈ 𝐷 ) ↔ ( [ 𝐴 / 𝑥 ] 𝑦 ∈ 𝐶 → [ 𝐴 / 𝑥 ] 𝑦 ∈ 𝐷 ) ) → ( [ 𝐴 / 𝑥 ] ( 𝑦 ∈ 𝐶 → 𝑦 ∈ 𝐷 ) ↔ ( 𝑦 ∈ ⦋ 𝐴 / 𝑥 ⦌ 𝐶 → 𝑦 ∈ ⦋ 𝐴 / 𝑥 ⦌ 𝐷 ) ) ) ) |
| 14 |
9 11 13
|
e11 |
⊢ ( 𝐴 ∈ 𝐵 ▶ ( [ 𝐴 / 𝑥 ] ( 𝑦 ∈ 𝐶 → 𝑦 ∈ 𝐷 ) ↔ ( 𝑦 ∈ ⦋ 𝐴 / 𝑥 ⦌ 𝐶 → 𝑦 ∈ ⦋ 𝐴 / 𝑥 ⦌ 𝐷 ) ) ) |
| 15 |
14
|
gen11 |
⊢ ( 𝐴 ∈ 𝐵 ▶ ∀ 𝑦 ( [ 𝐴 / 𝑥 ] ( 𝑦 ∈ 𝐶 → 𝑦 ∈ 𝐷 ) ↔ ( 𝑦 ∈ ⦋ 𝐴 / 𝑥 ⦌ 𝐶 → 𝑦 ∈ ⦋ 𝐴 / 𝑥 ⦌ 𝐷 ) ) ) |
| 16 |
|
albi |
⊢ ( ∀ 𝑦 ( [ 𝐴 / 𝑥 ] ( 𝑦 ∈ 𝐶 → 𝑦 ∈ 𝐷 ) ↔ ( 𝑦 ∈ ⦋ 𝐴 / 𝑥 ⦌ 𝐶 → 𝑦 ∈ ⦋ 𝐴 / 𝑥 ⦌ 𝐷 ) ) → ( ∀ 𝑦 [ 𝐴 / 𝑥 ] ( 𝑦 ∈ 𝐶 → 𝑦 ∈ 𝐷 ) ↔ ∀ 𝑦 ( 𝑦 ∈ ⦋ 𝐴 / 𝑥 ⦌ 𝐶 → 𝑦 ∈ ⦋ 𝐴 / 𝑥 ⦌ 𝐷 ) ) ) |
| 17 |
15 16
|
e1a |
⊢ ( 𝐴 ∈ 𝐵 ▶ ( ∀ 𝑦 [ 𝐴 / 𝑥 ] ( 𝑦 ∈ 𝐶 → 𝑦 ∈ 𝐷 ) ↔ ∀ 𝑦 ( 𝑦 ∈ ⦋ 𝐴 / 𝑥 ⦌ 𝐶 → 𝑦 ∈ ⦋ 𝐴 / 𝑥 ⦌ 𝐷 ) ) ) |
| 18 |
|
sbcal |
⊢ ( [ 𝐴 / 𝑥 ] ∀ 𝑦 ( 𝑦 ∈ 𝐶 → 𝑦 ∈ 𝐷 ) ↔ ∀ 𝑦 [ 𝐴 / 𝑥 ] ( 𝑦 ∈ 𝐶 → 𝑦 ∈ 𝐷 ) ) |
| 19 |
18
|
a1i |
⊢ ( 𝐴 ∈ 𝐵 → ( [ 𝐴 / 𝑥 ] ∀ 𝑦 ( 𝑦 ∈ 𝐶 → 𝑦 ∈ 𝐷 ) ↔ ∀ 𝑦 [ 𝐴 / 𝑥 ] ( 𝑦 ∈ 𝐶 → 𝑦 ∈ 𝐷 ) ) ) |
| 20 |
1 19
|
e1a |
⊢ ( 𝐴 ∈ 𝐵 ▶ ( [ 𝐴 / 𝑥 ] ∀ 𝑦 ( 𝑦 ∈ 𝐶 → 𝑦 ∈ 𝐷 ) ↔ ∀ 𝑦 [ 𝐴 / 𝑥 ] ( 𝑦 ∈ 𝐶 → 𝑦 ∈ 𝐷 ) ) ) |
| 21 |
|
bibi1 |
⊢ ( ( [ 𝐴 / 𝑥 ] ∀ 𝑦 ( 𝑦 ∈ 𝐶 → 𝑦 ∈ 𝐷 ) ↔ ∀ 𝑦 [ 𝐴 / 𝑥 ] ( 𝑦 ∈ 𝐶 → 𝑦 ∈ 𝐷 ) ) → ( ( [ 𝐴 / 𝑥 ] ∀ 𝑦 ( 𝑦 ∈ 𝐶 → 𝑦 ∈ 𝐷 ) ↔ ∀ 𝑦 ( 𝑦 ∈ ⦋ 𝐴 / 𝑥 ⦌ 𝐶 → 𝑦 ∈ ⦋ 𝐴 / 𝑥 ⦌ 𝐷 ) ) ↔ ( ∀ 𝑦 [ 𝐴 / 𝑥 ] ( 𝑦 ∈ 𝐶 → 𝑦 ∈ 𝐷 ) ↔ ∀ 𝑦 ( 𝑦 ∈ ⦋ 𝐴 / 𝑥 ⦌ 𝐶 → 𝑦 ∈ ⦋ 𝐴 / 𝑥 ⦌ 𝐷 ) ) ) ) |
| 22 |
21
|
biimprcd |
⊢ ( ( ∀ 𝑦 [ 𝐴 / 𝑥 ] ( 𝑦 ∈ 𝐶 → 𝑦 ∈ 𝐷 ) ↔ ∀ 𝑦 ( 𝑦 ∈ ⦋ 𝐴 / 𝑥 ⦌ 𝐶 → 𝑦 ∈ ⦋ 𝐴 / 𝑥 ⦌ 𝐷 ) ) → ( ( [ 𝐴 / 𝑥 ] ∀ 𝑦 ( 𝑦 ∈ 𝐶 → 𝑦 ∈ 𝐷 ) ↔ ∀ 𝑦 [ 𝐴 / 𝑥 ] ( 𝑦 ∈ 𝐶 → 𝑦 ∈ 𝐷 ) ) → ( [ 𝐴 / 𝑥 ] ∀ 𝑦 ( 𝑦 ∈ 𝐶 → 𝑦 ∈ 𝐷 ) ↔ ∀ 𝑦 ( 𝑦 ∈ ⦋ 𝐴 / 𝑥 ⦌ 𝐶 → 𝑦 ∈ ⦋ 𝐴 / 𝑥 ⦌ 𝐷 ) ) ) ) |
| 23 |
17 20 22
|
e11 |
⊢ ( 𝐴 ∈ 𝐵 ▶ ( [ 𝐴 / 𝑥 ] ∀ 𝑦 ( 𝑦 ∈ 𝐶 → 𝑦 ∈ 𝐷 ) ↔ ∀ 𝑦 ( 𝑦 ∈ ⦋ 𝐴 / 𝑥 ⦌ 𝐶 → 𝑦 ∈ ⦋ 𝐴 / 𝑥 ⦌ 𝐷 ) ) ) |
| 24 |
|
df-ss |
⊢ ( 𝐶 ⊆ 𝐷 ↔ ∀ 𝑦 ( 𝑦 ∈ 𝐶 → 𝑦 ∈ 𝐷 ) ) |
| 25 |
24
|
ax-gen |
⊢ ∀ 𝑥 ( 𝐶 ⊆ 𝐷 ↔ ∀ 𝑦 ( 𝑦 ∈ 𝐶 → 𝑦 ∈ 𝐷 ) ) |
| 26 |
|
sbcbi |
⊢ ( 𝐴 ∈ 𝐵 → ( ∀ 𝑥 ( 𝐶 ⊆ 𝐷 ↔ ∀ 𝑦 ( 𝑦 ∈ 𝐶 → 𝑦 ∈ 𝐷 ) ) → ( [ 𝐴 / 𝑥 ] 𝐶 ⊆ 𝐷 ↔ [ 𝐴 / 𝑥 ] ∀ 𝑦 ( 𝑦 ∈ 𝐶 → 𝑦 ∈ 𝐷 ) ) ) ) |
| 27 |
1 25 26
|
e10 |
⊢ ( 𝐴 ∈ 𝐵 ▶ ( [ 𝐴 / 𝑥 ] 𝐶 ⊆ 𝐷 ↔ [ 𝐴 / 𝑥 ] ∀ 𝑦 ( 𝑦 ∈ 𝐶 → 𝑦 ∈ 𝐷 ) ) ) |
| 28 |
|
bibi1 |
⊢ ( ( [ 𝐴 / 𝑥 ] 𝐶 ⊆ 𝐷 ↔ [ 𝐴 / 𝑥 ] ∀ 𝑦 ( 𝑦 ∈ 𝐶 → 𝑦 ∈ 𝐷 ) ) → ( ( [ 𝐴 / 𝑥 ] 𝐶 ⊆ 𝐷 ↔ ∀ 𝑦 ( 𝑦 ∈ ⦋ 𝐴 / 𝑥 ⦌ 𝐶 → 𝑦 ∈ ⦋ 𝐴 / 𝑥 ⦌ 𝐷 ) ) ↔ ( [ 𝐴 / 𝑥 ] ∀ 𝑦 ( 𝑦 ∈ 𝐶 → 𝑦 ∈ 𝐷 ) ↔ ∀ 𝑦 ( 𝑦 ∈ ⦋ 𝐴 / 𝑥 ⦌ 𝐶 → 𝑦 ∈ ⦋ 𝐴 / 𝑥 ⦌ 𝐷 ) ) ) ) |
| 29 |
28
|
biimprcd |
⊢ ( ( [ 𝐴 / 𝑥 ] ∀ 𝑦 ( 𝑦 ∈ 𝐶 → 𝑦 ∈ 𝐷 ) ↔ ∀ 𝑦 ( 𝑦 ∈ ⦋ 𝐴 / 𝑥 ⦌ 𝐶 → 𝑦 ∈ ⦋ 𝐴 / 𝑥 ⦌ 𝐷 ) ) → ( ( [ 𝐴 / 𝑥 ] 𝐶 ⊆ 𝐷 ↔ [ 𝐴 / 𝑥 ] ∀ 𝑦 ( 𝑦 ∈ 𝐶 → 𝑦 ∈ 𝐷 ) ) → ( [ 𝐴 / 𝑥 ] 𝐶 ⊆ 𝐷 ↔ ∀ 𝑦 ( 𝑦 ∈ ⦋ 𝐴 / 𝑥 ⦌ 𝐶 → 𝑦 ∈ ⦋ 𝐴 / 𝑥 ⦌ 𝐷 ) ) ) ) |
| 30 |
23 27 29
|
e11 |
⊢ ( 𝐴 ∈ 𝐵 ▶ ( [ 𝐴 / 𝑥 ] 𝐶 ⊆ 𝐷 ↔ ∀ 𝑦 ( 𝑦 ∈ ⦋ 𝐴 / 𝑥 ⦌ 𝐶 → 𝑦 ∈ ⦋ 𝐴 / 𝑥 ⦌ 𝐷 ) ) ) |
| 31 |
|
df-ss |
⊢ ( ⦋ 𝐴 / 𝑥 ⦌ 𝐶 ⊆ ⦋ 𝐴 / 𝑥 ⦌ 𝐷 ↔ ∀ 𝑦 ( 𝑦 ∈ ⦋ 𝐴 / 𝑥 ⦌ 𝐶 → 𝑦 ∈ ⦋ 𝐴 / 𝑥 ⦌ 𝐷 ) ) |
| 32 |
|
biantr |
⊢ ( ( ( [ 𝐴 / 𝑥 ] 𝐶 ⊆ 𝐷 ↔ ∀ 𝑦 ( 𝑦 ∈ ⦋ 𝐴 / 𝑥 ⦌ 𝐶 → 𝑦 ∈ ⦋ 𝐴 / 𝑥 ⦌ 𝐷 ) ) ∧ ( ⦋ 𝐴 / 𝑥 ⦌ 𝐶 ⊆ ⦋ 𝐴 / 𝑥 ⦌ 𝐷 ↔ ∀ 𝑦 ( 𝑦 ∈ ⦋ 𝐴 / 𝑥 ⦌ 𝐶 → 𝑦 ∈ ⦋ 𝐴 / 𝑥 ⦌ 𝐷 ) ) ) → ( [ 𝐴 / 𝑥 ] 𝐶 ⊆ 𝐷 ↔ ⦋ 𝐴 / 𝑥 ⦌ 𝐶 ⊆ ⦋ 𝐴 / 𝑥 ⦌ 𝐷 ) ) |
| 33 |
32
|
ex |
⊢ ( ( [ 𝐴 / 𝑥 ] 𝐶 ⊆ 𝐷 ↔ ∀ 𝑦 ( 𝑦 ∈ ⦋ 𝐴 / 𝑥 ⦌ 𝐶 → 𝑦 ∈ ⦋ 𝐴 / 𝑥 ⦌ 𝐷 ) ) → ( ( ⦋ 𝐴 / 𝑥 ⦌ 𝐶 ⊆ ⦋ 𝐴 / 𝑥 ⦌ 𝐷 ↔ ∀ 𝑦 ( 𝑦 ∈ ⦋ 𝐴 / 𝑥 ⦌ 𝐶 → 𝑦 ∈ ⦋ 𝐴 / 𝑥 ⦌ 𝐷 ) ) → ( [ 𝐴 / 𝑥 ] 𝐶 ⊆ 𝐷 ↔ ⦋ 𝐴 / 𝑥 ⦌ 𝐶 ⊆ ⦋ 𝐴 / 𝑥 ⦌ 𝐷 ) ) ) |
| 34 |
30 31 33
|
e10 |
⊢ ( 𝐴 ∈ 𝐵 ▶ ( [ 𝐴 / 𝑥 ] 𝐶 ⊆ 𝐷 ↔ ⦋ 𝐴 / 𝑥 ⦌ 𝐶 ⊆ ⦋ 𝐴 / 𝑥 ⦌ 𝐷 ) ) |
| 35 |
34
|
in1 |
⊢ ( 𝐴 ∈ 𝐵 → ( [ 𝐴 / 𝑥 ] 𝐶 ⊆ 𝐷 ↔ ⦋ 𝐴 / 𝑥 ⦌ 𝐶 ⊆ ⦋ 𝐴 / 𝑥 ⦌ 𝐷 ) ) |