Step |
Hyp |
Ref |
Expression |
1 |
|
reurab.1 |
⊢ ( 𝑥 = 𝑦 → ( 𝜑 ↔ 𝜓 ) ) |
2 |
1
|
bicomd |
⊢ ( 𝑥 = 𝑦 → ( 𝜓 ↔ 𝜑 ) ) |
3 |
2
|
equcoms |
⊢ ( 𝑦 = 𝑥 → ( 𝜓 ↔ 𝜑 ) ) |
4 |
3
|
elrab |
⊢ ( 𝑥 ∈ { 𝑦 ∈ 𝐴 ∣ 𝜓 } ↔ ( 𝑥 ∈ 𝐴 ∧ 𝜑 ) ) |
5 |
4
|
anbi1i |
⊢ ( ( 𝑥 ∈ { 𝑦 ∈ 𝐴 ∣ 𝜓 } ∧ 𝜒 ) ↔ ( ( 𝑥 ∈ 𝐴 ∧ 𝜑 ) ∧ 𝜒 ) ) |
6 |
|
anass |
⊢ ( ( ( 𝑥 ∈ 𝐴 ∧ 𝜑 ) ∧ 𝜒 ) ↔ ( 𝑥 ∈ 𝐴 ∧ ( 𝜑 ∧ 𝜒 ) ) ) |
7 |
5 6
|
bitri |
⊢ ( ( 𝑥 ∈ { 𝑦 ∈ 𝐴 ∣ 𝜓 } ∧ 𝜒 ) ↔ ( 𝑥 ∈ 𝐴 ∧ ( 𝜑 ∧ 𝜒 ) ) ) |
8 |
7
|
eubii |
⊢ ( ∃! 𝑥 ( 𝑥 ∈ { 𝑦 ∈ 𝐴 ∣ 𝜓 } ∧ 𝜒 ) ↔ ∃! 𝑥 ( 𝑥 ∈ 𝐴 ∧ ( 𝜑 ∧ 𝜒 ) ) ) |
9 |
|
df-reu |
⊢ ( ∃! 𝑥 ∈ { 𝑦 ∈ 𝐴 ∣ 𝜓 } 𝜒 ↔ ∃! 𝑥 ( 𝑥 ∈ { 𝑦 ∈ 𝐴 ∣ 𝜓 } ∧ 𝜒 ) ) |
10 |
|
df-reu |
⊢ ( ∃! 𝑥 ∈ 𝐴 ( 𝜑 ∧ 𝜒 ) ↔ ∃! 𝑥 ( 𝑥 ∈ 𝐴 ∧ ( 𝜑 ∧ 𝜒 ) ) ) |
11 |
8 9 10
|
3bitr4i |
⊢ ( ∃! 𝑥 ∈ { 𝑦 ∈ 𝐴 ∣ 𝜓 } 𝜒 ↔ ∃! 𝑥 ∈ 𝐴 ( 𝜑 ∧ 𝜒 ) ) |