| Step |
Hyp |
Ref |
Expression |
| 1 |
|
difeq2 |
⊢ ( 𝑢 = 𝑥 → ( 𝐴 ∖ 𝑢 ) = ( 𝐴 ∖ 𝑥 ) ) |
| 2 |
1
|
eleq1d |
⊢ ( 𝑢 = 𝑥 → ( ( 𝐴 ∖ 𝑢 ) ∈ 𝑌 ↔ ( 𝐴 ∖ 𝑥 ) ∈ 𝑌 ) ) |
| 3 |
2
|
elrab |
⊢ ( 𝑥 ∈ { 𝑢 ∈ 𝒫 𝐴 ∣ ( 𝐴 ∖ 𝑢 ) ∈ 𝑌 } ↔ ( 𝑥 ∈ 𝒫 𝐴 ∧ ( 𝐴 ∖ 𝑥 ) ∈ 𝑌 ) ) |
| 4 |
|
difeq2 |
⊢ ( 𝑢 = 𝑦 → ( 𝐴 ∖ 𝑢 ) = ( 𝐴 ∖ 𝑦 ) ) |
| 5 |
4
|
eleq1d |
⊢ ( 𝑢 = 𝑦 → ( ( 𝐴 ∖ 𝑢 ) ∈ 𝑌 ↔ ( 𝐴 ∖ 𝑦 ) ∈ 𝑌 ) ) |
| 6 |
5
|
elrab |
⊢ ( 𝑦 ∈ { 𝑢 ∈ 𝒫 𝐴 ∣ ( 𝐴 ∖ 𝑢 ) ∈ 𝑌 } ↔ ( 𝑦 ∈ 𝒫 𝐴 ∧ ( 𝐴 ∖ 𝑦 ) ∈ 𝑌 ) ) |
| 7 |
|
an4 |
⊢ ( ( ( 𝑥 ∈ 𝒫 𝐴 ∧ ( 𝐴 ∖ 𝑥 ) ∈ 𝑌 ) ∧ ( 𝑦 ∈ 𝒫 𝐴 ∧ ( 𝐴 ∖ 𝑦 ) ∈ 𝑌 ) ) ↔ ( ( 𝑥 ∈ 𝒫 𝐴 ∧ 𝑦 ∈ 𝒫 𝐴 ) ∧ ( ( 𝐴 ∖ 𝑥 ) ∈ 𝑌 ∧ ( 𝐴 ∖ 𝑦 ) ∈ 𝑌 ) ) ) |
| 8 |
7
|
biimpi |
⊢ ( ( ( 𝑥 ∈ 𝒫 𝐴 ∧ ( 𝐴 ∖ 𝑥 ) ∈ 𝑌 ) ∧ ( 𝑦 ∈ 𝒫 𝐴 ∧ ( 𝐴 ∖ 𝑦 ) ∈ 𝑌 ) ) → ( ( 𝑥 ∈ 𝒫 𝐴 ∧ 𝑦 ∈ 𝒫 𝐴 ) ∧ ( ( 𝐴 ∖ 𝑥 ) ∈ 𝑌 ∧ ( 𝐴 ∖ 𝑦 ) ∈ 𝑌 ) ) ) |
| 9 |
3 6 8
|
syl2anb |
⊢ ( ( 𝑥 ∈ { 𝑢 ∈ 𝒫 𝐴 ∣ ( 𝐴 ∖ 𝑢 ) ∈ 𝑌 } ∧ 𝑦 ∈ { 𝑢 ∈ 𝒫 𝐴 ∣ ( 𝐴 ∖ 𝑢 ) ∈ 𝑌 } ) → ( ( 𝑥 ∈ 𝒫 𝐴 ∧ 𝑦 ∈ 𝒫 𝐴 ) ∧ ( ( 𝐴 ∖ 𝑥 ) ∈ 𝑌 ∧ ( 𝐴 ∖ 𝑦 ) ∈ 𝑌 ) ) ) |
| 10 |
|
sorpssi |
⊢ ( ( [⊊] Or 𝑌 ∧ ( ( 𝐴 ∖ 𝑥 ) ∈ 𝑌 ∧ ( 𝐴 ∖ 𝑦 ) ∈ 𝑌 ) ) → ( ( 𝐴 ∖ 𝑥 ) ⊆ ( 𝐴 ∖ 𝑦 ) ∨ ( 𝐴 ∖ 𝑦 ) ⊆ ( 𝐴 ∖ 𝑥 ) ) ) |
| 11 |
10
|
expcom |
⊢ ( ( ( 𝐴 ∖ 𝑥 ) ∈ 𝑌 ∧ ( 𝐴 ∖ 𝑦 ) ∈ 𝑌 ) → ( [⊊] Or 𝑌 → ( ( 𝐴 ∖ 𝑥 ) ⊆ ( 𝐴 ∖ 𝑦 ) ∨ ( 𝐴 ∖ 𝑦 ) ⊆ ( 𝐴 ∖ 𝑥 ) ) ) ) |
| 12 |
|
velpw |
⊢ ( 𝑥 ∈ 𝒫 𝐴 ↔ 𝑥 ⊆ 𝐴 ) |
| 13 |
|
dfss4 |
⊢ ( 𝑥 ⊆ 𝐴 ↔ ( 𝐴 ∖ ( 𝐴 ∖ 𝑥 ) ) = 𝑥 ) |
| 14 |
12 13
|
bitri |
⊢ ( 𝑥 ∈ 𝒫 𝐴 ↔ ( 𝐴 ∖ ( 𝐴 ∖ 𝑥 ) ) = 𝑥 ) |
| 15 |
|
velpw |
⊢ ( 𝑦 ∈ 𝒫 𝐴 ↔ 𝑦 ⊆ 𝐴 ) |
| 16 |
|
dfss4 |
⊢ ( 𝑦 ⊆ 𝐴 ↔ ( 𝐴 ∖ ( 𝐴 ∖ 𝑦 ) ) = 𝑦 ) |
| 17 |
15 16
|
bitri |
⊢ ( 𝑦 ∈ 𝒫 𝐴 ↔ ( 𝐴 ∖ ( 𝐴 ∖ 𝑦 ) ) = 𝑦 ) |
| 18 |
|
sscon |
⊢ ( ( 𝐴 ∖ 𝑦 ) ⊆ ( 𝐴 ∖ 𝑥 ) → ( 𝐴 ∖ ( 𝐴 ∖ 𝑥 ) ) ⊆ ( 𝐴 ∖ ( 𝐴 ∖ 𝑦 ) ) ) |
| 19 |
|
sseq12 |
⊢ ( ( ( 𝐴 ∖ ( 𝐴 ∖ 𝑥 ) ) = 𝑥 ∧ ( 𝐴 ∖ ( 𝐴 ∖ 𝑦 ) ) = 𝑦 ) → ( ( 𝐴 ∖ ( 𝐴 ∖ 𝑥 ) ) ⊆ ( 𝐴 ∖ ( 𝐴 ∖ 𝑦 ) ) ↔ 𝑥 ⊆ 𝑦 ) ) |
| 20 |
18 19
|
imbitrid |
⊢ ( ( ( 𝐴 ∖ ( 𝐴 ∖ 𝑥 ) ) = 𝑥 ∧ ( 𝐴 ∖ ( 𝐴 ∖ 𝑦 ) ) = 𝑦 ) → ( ( 𝐴 ∖ 𝑦 ) ⊆ ( 𝐴 ∖ 𝑥 ) → 𝑥 ⊆ 𝑦 ) ) |
| 21 |
|
sscon |
⊢ ( ( 𝐴 ∖ 𝑥 ) ⊆ ( 𝐴 ∖ 𝑦 ) → ( 𝐴 ∖ ( 𝐴 ∖ 𝑦 ) ) ⊆ ( 𝐴 ∖ ( 𝐴 ∖ 𝑥 ) ) ) |
| 22 |
|
sseq12 |
⊢ ( ( ( 𝐴 ∖ ( 𝐴 ∖ 𝑦 ) ) = 𝑦 ∧ ( 𝐴 ∖ ( 𝐴 ∖ 𝑥 ) ) = 𝑥 ) → ( ( 𝐴 ∖ ( 𝐴 ∖ 𝑦 ) ) ⊆ ( 𝐴 ∖ ( 𝐴 ∖ 𝑥 ) ) ↔ 𝑦 ⊆ 𝑥 ) ) |
| 23 |
22
|
ancoms |
⊢ ( ( ( 𝐴 ∖ ( 𝐴 ∖ 𝑥 ) ) = 𝑥 ∧ ( 𝐴 ∖ ( 𝐴 ∖ 𝑦 ) ) = 𝑦 ) → ( ( 𝐴 ∖ ( 𝐴 ∖ 𝑦 ) ) ⊆ ( 𝐴 ∖ ( 𝐴 ∖ 𝑥 ) ) ↔ 𝑦 ⊆ 𝑥 ) ) |
| 24 |
21 23
|
imbitrid |
⊢ ( ( ( 𝐴 ∖ ( 𝐴 ∖ 𝑥 ) ) = 𝑥 ∧ ( 𝐴 ∖ ( 𝐴 ∖ 𝑦 ) ) = 𝑦 ) → ( ( 𝐴 ∖ 𝑥 ) ⊆ ( 𝐴 ∖ 𝑦 ) → 𝑦 ⊆ 𝑥 ) ) |
| 25 |
20 24
|
orim12d |
⊢ ( ( ( 𝐴 ∖ ( 𝐴 ∖ 𝑥 ) ) = 𝑥 ∧ ( 𝐴 ∖ ( 𝐴 ∖ 𝑦 ) ) = 𝑦 ) → ( ( ( 𝐴 ∖ 𝑦 ) ⊆ ( 𝐴 ∖ 𝑥 ) ∨ ( 𝐴 ∖ 𝑥 ) ⊆ ( 𝐴 ∖ 𝑦 ) ) → ( 𝑥 ⊆ 𝑦 ∨ 𝑦 ⊆ 𝑥 ) ) ) |
| 26 |
14 17 25
|
syl2anb |
⊢ ( ( 𝑥 ∈ 𝒫 𝐴 ∧ 𝑦 ∈ 𝒫 𝐴 ) → ( ( ( 𝐴 ∖ 𝑦 ) ⊆ ( 𝐴 ∖ 𝑥 ) ∨ ( 𝐴 ∖ 𝑥 ) ⊆ ( 𝐴 ∖ 𝑦 ) ) → ( 𝑥 ⊆ 𝑦 ∨ 𝑦 ⊆ 𝑥 ) ) ) |
| 27 |
26
|
com12 |
⊢ ( ( ( 𝐴 ∖ 𝑦 ) ⊆ ( 𝐴 ∖ 𝑥 ) ∨ ( 𝐴 ∖ 𝑥 ) ⊆ ( 𝐴 ∖ 𝑦 ) ) → ( ( 𝑥 ∈ 𝒫 𝐴 ∧ 𝑦 ∈ 𝒫 𝐴 ) → ( 𝑥 ⊆ 𝑦 ∨ 𝑦 ⊆ 𝑥 ) ) ) |
| 28 |
27
|
orcoms |
⊢ ( ( ( 𝐴 ∖ 𝑥 ) ⊆ ( 𝐴 ∖ 𝑦 ) ∨ ( 𝐴 ∖ 𝑦 ) ⊆ ( 𝐴 ∖ 𝑥 ) ) → ( ( 𝑥 ∈ 𝒫 𝐴 ∧ 𝑦 ∈ 𝒫 𝐴 ) → ( 𝑥 ⊆ 𝑦 ∨ 𝑦 ⊆ 𝑥 ) ) ) |
| 29 |
11 28
|
syl6 |
⊢ ( ( ( 𝐴 ∖ 𝑥 ) ∈ 𝑌 ∧ ( 𝐴 ∖ 𝑦 ) ∈ 𝑌 ) → ( [⊊] Or 𝑌 → ( ( 𝑥 ∈ 𝒫 𝐴 ∧ 𝑦 ∈ 𝒫 𝐴 ) → ( 𝑥 ⊆ 𝑦 ∨ 𝑦 ⊆ 𝑥 ) ) ) ) |
| 30 |
29
|
com3l |
⊢ ( [⊊] Or 𝑌 → ( ( 𝑥 ∈ 𝒫 𝐴 ∧ 𝑦 ∈ 𝒫 𝐴 ) → ( ( ( 𝐴 ∖ 𝑥 ) ∈ 𝑌 ∧ ( 𝐴 ∖ 𝑦 ) ∈ 𝑌 ) → ( 𝑥 ⊆ 𝑦 ∨ 𝑦 ⊆ 𝑥 ) ) ) ) |
| 31 |
30
|
impd |
⊢ ( [⊊] Or 𝑌 → ( ( ( 𝑥 ∈ 𝒫 𝐴 ∧ 𝑦 ∈ 𝒫 𝐴 ) ∧ ( ( 𝐴 ∖ 𝑥 ) ∈ 𝑌 ∧ ( 𝐴 ∖ 𝑦 ) ∈ 𝑌 ) ) → ( 𝑥 ⊆ 𝑦 ∨ 𝑦 ⊆ 𝑥 ) ) ) |
| 32 |
9 31
|
syl5 |
⊢ ( [⊊] Or 𝑌 → ( ( 𝑥 ∈ { 𝑢 ∈ 𝒫 𝐴 ∣ ( 𝐴 ∖ 𝑢 ) ∈ 𝑌 } ∧ 𝑦 ∈ { 𝑢 ∈ 𝒫 𝐴 ∣ ( 𝐴 ∖ 𝑢 ) ∈ 𝑌 } ) → ( 𝑥 ⊆ 𝑦 ∨ 𝑦 ⊆ 𝑥 ) ) ) |
| 33 |
32
|
ralrimivv |
⊢ ( [⊊] Or 𝑌 → ∀ 𝑥 ∈ { 𝑢 ∈ 𝒫 𝐴 ∣ ( 𝐴 ∖ 𝑢 ) ∈ 𝑌 } ∀ 𝑦 ∈ { 𝑢 ∈ 𝒫 𝐴 ∣ ( 𝐴 ∖ 𝑢 ) ∈ 𝑌 } ( 𝑥 ⊆ 𝑦 ∨ 𝑦 ⊆ 𝑥 ) ) |
| 34 |
|
sorpss |
⊢ ( [⊊] Or { 𝑢 ∈ 𝒫 𝐴 ∣ ( 𝐴 ∖ 𝑢 ) ∈ 𝑌 } ↔ ∀ 𝑥 ∈ { 𝑢 ∈ 𝒫 𝐴 ∣ ( 𝐴 ∖ 𝑢 ) ∈ 𝑌 } ∀ 𝑦 ∈ { 𝑢 ∈ 𝒫 𝐴 ∣ ( 𝐴 ∖ 𝑢 ) ∈ 𝑌 } ( 𝑥 ⊆ 𝑦 ∨ 𝑦 ⊆ 𝑥 ) ) |
| 35 |
33 34
|
sylibr |
⊢ ( [⊊] Or 𝑌 → [⊊] Or { 𝑢 ∈ 𝒫 𝐴 ∣ ( 𝐴 ∖ 𝑢 ) ∈ 𝑌 } ) |