Step |
Hyp |
Ref |
Expression |
1 |
|
df-rex |
⊢ ( ∃ 𝑦 ∈ Univ 𝑥 ∈ 𝑦 ↔ ∃ 𝑦 ( 𝑦 ∈ Univ ∧ 𝑥 ∈ 𝑦 ) ) |
2 |
|
exancom |
⊢ ( ∃ 𝑦 ( 𝑦 ∈ Univ ∧ 𝑥 ∈ 𝑦 ) ↔ ∃ 𝑦 ( 𝑥 ∈ 𝑦 ∧ 𝑦 ∈ Univ ) ) |
3 |
|
dfuniv2 |
⊢ Univ = { 𝑦 ∣ ∀ 𝑧 ∈ 𝑦 ∀ 𝑓 ∈ 𝒫 𝑦 ∃ 𝑤 ∈ 𝑦 ( 𝒫 𝑧 ⊆ ( 𝑦 ∩ 𝑤 ) ∧ ( 𝑧 ∩ ∪ 𝑓 ) ⊆ ∪ ( 𝑓 ∩ 𝒫 𝒫 𝑤 ) ) } |
4 |
3
|
abeq2i |
⊢ ( 𝑦 ∈ Univ ↔ ∀ 𝑧 ∈ 𝑦 ∀ 𝑓 ∈ 𝒫 𝑦 ∃ 𝑤 ∈ 𝑦 ( 𝒫 𝑧 ⊆ ( 𝑦 ∩ 𝑤 ) ∧ ( 𝑧 ∩ ∪ 𝑓 ) ⊆ ∪ ( 𝑓 ∩ 𝒫 𝒫 𝑤 ) ) ) |
5 |
4
|
anbi2i |
⊢ ( ( 𝑥 ∈ 𝑦 ∧ 𝑦 ∈ Univ ) ↔ ( 𝑥 ∈ 𝑦 ∧ ∀ 𝑧 ∈ 𝑦 ∀ 𝑓 ∈ 𝒫 𝑦 ∃ 𝑤 ∈ 𝑦 ( 𝒫 𝑧 ⊆ ( 𝑦 ∩ 𝑤 ) ∧ ( 𝑧 ∩ ∪ 𝑓 ) ⊆ ∪ ( 𝑓 ∩ 𝒫 𝒫 𝑤 ) ) ) ) |
6 |
5
|
exbii |
⊢ ( ∃ 𝑦 ( 𝑥 ∈ 𝑦 ∧ 𝑦 ∈ Univ ) ↔ ∃ 𝑦 ( 𝑥 ∈ 𝑦 ∧ ∀ 𝑧 ∈ 𝑦 ∀ 𝑓 ∈ 𝒫 𝑦 ∃ 𝑤 ∈ 𝑦 ( 𝒫 𝑧 ⊆ ( 𝑦 ∩ 𝑤 ) ∧ ( 𝑧 ∩ ∪ 𝑓 ) ⊆ ∪ ( 𝑓 ∩ 𝒫 𝒫 𝑤 ) ) ) ) |
7 |
1 2 6
|
3bitri |
⊢ ( ∃ 𝑦 ∈ Univ 𝑥 ∈ 𝑦 ↔ ∃ 𝑦 ( 𝑥 ∈ 𝑦 ∧ ∀ 𝑧 ∈ 𝑦 ∀ 𝑓 ∈ 𝒫 𝑦 ∃ 𝑤 ∈ 𝑦 ( 𝒫 𝑧 ⊆ ( 𝑦 ∩ 𝑤 ) ∧ ( 𝑧 ∩ ∪ 𝑓 ) ⊆ ∪ ( 𝑓 ∩ 𝒫 𝒫 𝑤 ) ) ) ) |
8 |
7
|
albii |
⊢ ( ∀ 𝑥 ∃ 𝑦 ∈ Univ 𝑥 ∈ 𝑦 ↔ ∀ 𝑥 ∃ 𝑦 ( 𝑥 ∈ 𝑦 ∧ ∀ 𝑧 ∈ 𝑦 ∀ 𝑓 ∈ 𝒫 𝑦 ∃ 𝑤 ∈ 𝑦 ( 𝒫 𝑧 ⊆ ( 𝑦 ∩ 𝑤 ) ∧ ( 𝑧 ∩ ∪ 𝑓 ) ⊆ ∪ ( 𝑓 ∩ 𝒫 𝒫 𝑤 ) ) ) ) |