Step | Hyp | Ref
| Expression |
1 | | eleq1 2233 |
. . . . . 6
⊢ (𝐴 = 𝐵 → (𝐴 ∈ V ↔ 𝐵 ∈ V)) |
2 | 1 | anbi1d 462 |
. . . . 5
⊢ (𝐴 = 𝐵 → ((𝐴 ∈ V ∧ 𝐶 ∈ V) ↔ (𝐵 ∈ V ∧ 𝐶 ∈ V))) |
3 | | sneq 3592 |
. . . . . . 7
⊢ (𝐴 = 𝐵 → {𝐴} = {𝐵}) |
4 | | preq1 3658 |
. . . . . . 7
⊢ (𝐴 = 𝐵 → {𝐴, 𝐶} = {𝐵, 𝐶}) |
5 | 3, 4 | preq12d 3666 |
. . . . . 6
⊢ (𝐴 = 𝐵 → {{𝐴}, {𝐴, 𝐶}} = {{𝐵}, {𝐵, 𝐶}}) |
6 | 5 | eleq2d 2240 |
. . . . 5
⊢ (𝐴 = 𝐵 → (𝑥 ∈ {{𝐴}, {𝐴, 𝐶}} ↔ 𝑥 ∈ {{𝐵}, {𝐵, 𝐶}})) |
7 | 2, 6 | anbi12d 470 |
. . . 4
⊢ (𝐴 = 𝐵 → (((𝐴 ∈ V ∧ 𝐶 ∈ V) ∧ 𝑥 ∈ {{𝐴}, {𝐴, 𝐶}}) ↔ ((𝐵 ∈ V ∧ 𝐶 ∈ V) ∧ 𝑥 ∈ {{𝐵}, {𝐵, 𝐶}}))) |
8 | | df-3an 975 |
. . . 4
⊢ ((𝐴 ∈ V ∧ 𝐶 ∈ V ∧ 𝑥 ∈ {{𝐴}, {𝐴, 𝐶}}) ↔ ((𝐴 ∈ V ∧ 𝐶 ∈ V) ∧ 𝑥 ∈ {{𝐴}, {𝐴, 𝐶}})) |
9 | | df-3an 975 |
. . . 4
⊢ ((𝐵 ∈ V ∧ 𝐶 ∈ V ∧ 𝑥 ∈ {{𝐵}, {𝐵, 𝐶}}) ↔ ((𝐵 ∈ V ∧ 𝐶 ∈ V) ∧ 𝑥 ∈ {{𝐵}, {𝐵, 𝐶}})) |
10 | 7, 8, 9 | 3bitr4g 222 |
. . 3
⊢ (𝐴 = 𝐵 → ((𝐴 ∈ V ∧ 𝐶 ∈ V ∧ 𝑥 ∈ {{𝐴}, {𝐴, 𝐶}}) ↔ (𝐵 ∈ V ∧ 𝐶 ∈ V ∧ 𝑥 ∈ {{𝐵}, {𝐵, 𝐶}}))) |
11 | 10 | abbidv 2288 |
. 2
⊢ (𝐴 = 𝐵 → {𝑥 ∣ (𝐴 ∈ V ∧ 𝐶 ∈ V ∧ 𝑥 ∈ {{𝐴}, {𝐴, 𝐶}})} = {𝑥 ∣ (𝐵 ∈ V ∧ 𝐶 ∈ V ∧ 𝑥 ∈ {{𝐵}, {𝐵, 𝐶}})}) |
12 | | df-op 3590 |
. 2
⊢
〈𝐴, 𝐶〉 = {𝑥 ∣ (𝐴 ∈ V ∧ 𝐶 ∈ V ∧ 𝑥 ∈ {{𝐴}, {𝐴, 𝐶}})} |
13 | | df-op 3590 |
. 2
⊢
〈𝐵, 𝐶〉 = {𝑥 ∣ (𝐵 ∈ V ∧ 𝐶 ∈ V ∧ 𝑥 ∈ {{𝐵}, {𝐵, 𝐶}})} |
14 | 11, 12, 13 | 3eqtr4g 2228 |
1
⊢ (𝐴 = 𝐵 → 〈𝐴, 𝐶〉 = 〈𝐵, 𝐶〉) |