Step |
Hyp |
Ref |
Expression |
1 |
|
elrab2w.1 |
⊢ ( 𝑥 = 𝑦 → ( 𝜑 ↔ 𝜓 ) ) |
2 |
|
elrab2w.2 |
⊢ ( 𝑦 = 𝐴 → ( 𝜓 ↔ 𝜒 ) ) |
3 |
|
elrab2w.3 |
⊢ 𝐶 = { 𝑥 ∈ 𝐵 ∣ 𝜑 } |
4 |
|
elex |
⊢ ( 𝐴 ∈ 𝐶 → 𝐴 ∈ V ) |
5 |
|
elex |
⊢ ( 𝐴 ∈ 𝐵 → 𝐴 ∈ V ) |
6 |
5
|
adantr |
⊢ ( ( 𝐴 ∈ 𝐵 ∧ 𝜒 ) → 𝐴 ∈ V ) |
7 |
|
eleq1w |
⊢ ( 𝑥 = 𝑦 → ( 𝑥 ∈ 𝐵 ↔ 𝑦 ∈ 𝐵 ) ) |
8 |
7 1
|
anbi12d |
⊢ ( 𝑥 = 𝑦 → ( ( 𝑥 ∈ 𝐵 ∧ 𝜑 ) ↔ ( 𝑦 ∈ 𝐵 ∧ 𝜓 ) ) ) |
9 |
|
eleq1 |
⊢ ( 𝑦 = 𝐴 → ( 𝑦 ∈ 𝐵 ↔ 𝐴 ∈ 𝐵 ) ) |
10 |
9 2
|
anbi12d |
⊢ ( 𝑦 = 𝐴 → ( ( 𝑦 ∈ 𝐵 ∧ 𝜓 ) ↔ ( 𝐴 ∈ 𝐵 ∧ 𝜒 ) ) ) |
11 |
|
df-rab |
⊢ { 𝑥 ∈ 𝐵 ∣ 𝜑 } = { 𝑥 ∣ ( 𝑥 ∈ 𝐵 ∧ 𝜑 ) } |
12 |
3 11
|
eqtri |
⊢ 𝐶 = { 𝑥 ∣ ( 𝑥 ∈ 𝐵 ∧ 𝜑 ) } |
13 |
8 10 12
|
elab2gw |
⊢ ( 𝐴 ∈ V → ( 𝐴 ∈ 𝐶 ↔ ( 𝐴 ∈ 𝐵 ∧ 𝜒 ) ) ) |
14 |
4 6 13
|
pm5.21nii |
⊢ ( 𝐴 ∈ 𝐶 ↔ ( 𝐴 ∈ 𝐵 ∧ 𝜒 ) ) |