Step | Hyp | Ref
| Expression |
1 | | eqeq1 2614 |
. . . . . . 7
⊢ (𝑥 = 𝐴 → (𝑥 = 𝑦 ↔ 𝐴 = 𝑦)) |
2 | 1 | notbid 307 |
. . . . . 6
⊢ (𝑥 = 𝐴 → (¬ 𝑥 = 𝑦 ↔ ¬ 𝐴 = 𝑦)) |
3 | | preq1 4212 |
. . . . . . . 8
⊢ (𝑥 = 𝐴 → {𝑥, 𝑦} = {𝐴, 𝑦}) |
4 | 3 | eqeq1d 2612 |
. . . . . . 7
⊢ (𝑥 = 𝐴 → ({𝑥, 𝑦} = {𝑧, 𝐷} ↔ {𝐴, 𝑦} = {𝑧, 𝐷})) |
5 | | eleq1 2676 |
. . . . . . . 8
⊢ (𝑥 = 𝐴 → (𝑥 ∈ {𝑧, 𝐷} ↔ 𝐴 ∈ {𝑧, 𝐷})) |
6 | 5 | anbi1d 737 |
. . . . . . 7
⊢ (𝑥 = 𝐴 → ((𝑥 ∈ {𝑧, 𝐷} ∧ 𝑦 ∈ {𝑧, 𝐷}) ↔ (𝐴 ∈ {𝑧, 𝐷} ∧ 𝑦 ∈ {𝑧, 𝐷}))) |
7 | 4, 6 | bibi12d 334 |
. . . . . 6
⊢ (𝑥 = 𝐴 → (({𝑥, 𝑦} = {𝑧, 𝐷} ↔ (𝑥 ∈ {𝑧, 𝐷} ∧ 𝑦 ∈ {𝑧, 𝐷})) ↔ ({𝐴, 𝑦} = {𝑧, 𝐷} ↔ (𝐴 ∈ {𝑧, 𝐷} ∧ 𝑦 ∈ {𝑧, 𝐷})))) |
8 | 2, 7 | imbi12d 333 |
. . . . 5
⊢ (𝑥 = 𝐴 → ((¬ 𝑥 = 𝑦 → ({𝑥, 𝑦} = {𝑧, 𝐷} ↔ (𝑥 ∈ {𝑧, 𝐷} ∧ 𝑦 ∈ {𝑧, 𝐷}))) ↔ (¬ 𝐴 = 𝑦 → ({𝐴, 𝑦} = {𝑧, 𝐷} ↔ (𝐴 ∈ {𝑧, 𝐷} ∧ 𝑦 ∈ {𝑧, 𝐷}))))) |
9 | 8 | imbi2d 329 |
. . . 4
⊢ (𝑥 = 𝐴 → ((𝐷 ∈ 𝑌 → (¬ 𝑥 = 𝑦 → ({𝑥, 𝑦} = {𝑧, 𝐷} ↔ (𝑥 ∈ {𝑧, 𝐷} ∧ 𝑦 ∈ {𝑧, 𝐷})))) ↔ (𝐷 ∈ 𝑌 → (¬ 𝐴 = 𝑦 → ({𝐴, 𝑦} = {𝑧, 𝐷} ↔ (𝐴 ∈ {𝑧, 𝐷} ∧ 𝑦 ∈ {𝑧, 𝐷})))))) |
10 | | eqeq2 2621 |
. . . . . . 7
⊢ (𝑦 = 𝐵 → (𝐴 = 𝑦 ↔ 𝐴 = 𝐵)) |
11 | 10 | notbid 307 |
. . . . . 6
⊢ (𝑦 = 𝐵 → (¬ 𝐴 = 𝑦 ↔ ¬ 𝐴 = 𝐵)) |
12 | | preq2 4213 |
. . . . . . . 8
⊢ (𝑦 = 𝐵 → {𝐴, 𝑦} = {𝐴, 𝐵}) |
13 | 12 | eqeq1d 2612 |
. . . . . . 7
⊢ (𝑦 = 𝐵 → ({𝐴, 𝑦} = {𝑧, 𝐷} ↔ {𝐴, 𝐵} = {𝑧, 𝐷})) |
14 | | eleq1 2676 |
. . . . . . . 8
⊢ (𝑦 = 𝐵 → (𝑦 ∈ {𝑧, 𝐷} ↔ 𝐵 ∈ {𝑧, 𝐷})) |
15 | 14 | anbi2d 736 |
. . . . . . 7
⊢ (𝑦 = 𝐵 → ((𝐴 ∈ {𝑧, 𝐷} ∧ 𝑦 ∈ {𝑧, 𝐷}) ↔ (𝐴 ∈ {𝑧, 𝐷} ∧ 𝐵 ∈ {𝑧, 𝐷}))) |
16 | 13, 15 | bibi12d 334 |
. . . . . 6
⊢ (𝑦 = 𝐵 → (({𝐴, 𝑦} = {𝑧, 𝐷} ↔ (𝐴 ∈ {𝑧, 𝐷} ∧ 𝑦 ∈ {𝑧, 𝐷})) ↔ ({𝐴, 𝐵} = {𝑧, 𝐷} ↔ (𝐴 ∈ {𝑧, 𝐷} ∧ 𝐵 ∈ {𝑧, 𝐷})))) |
17 | 11, 16 | imbi12d 333 |
. . . . 5
⊢ (𝑦 = 𝐵 → ((¬ 𝐴 = 𝑦 → ({𝐴, 𝑦} = {𝑧, 𝐷} ↔ (𝐴 ∈ {𝑧, 𝐷} ∧ 𝑦 ∈ {𝑧, 𝐷}))) ↔ (¬ 𝐴 = 𝐵 → ({𝐴, 𝐵} = {𝑧, 𝐷} ↔ (𝐴 ∈ {𝑧, 𝐷} ∧ 𝐵 ∈ {𝑧, 𝐷}))))) |
18 | 17 | imbi2d 329 |
. . . 4
⊢ (𝑦 = 𝐵 → ((𝐷 ∈ 𝑌 → (¬ 𝐴 = 𝑦 → ({𝐴, 𝑦} = {𝑧, 𝐷} ↔ (𝐴 ∈ {𝑧, 𝐷} ∧ 𝑦 ∈ {𝑧, 𝐷})))) ↔ (𝐷 ∈ 𝑌 → (¬ 𝐴 = 𝐵 → ({𝐴, 𝐵} = {𝑧, 𝐷} ↔ (𝐴 ∈ {𝑧, 𝐷} ∧ 𝐵 ∈ {𝑧, 𝐷})))))) |
19 | | preq1 4212 |
. . . . . . . 8
⊢ (𝑧 = 𝐶 → {𝑧, 𝐷} = {𝐶, 𝐷}) |
20 | 19 | eqeq2d 2620 |
. . . . . . 7
⊢ (𝑧 = 𝐶 → ({𝐴, 𝐵} = {𝑧, 𝐷} ↔ {𝐴, 𝐵} = {𝐶, 𝐷})) |
21 | 19 | eleq2d 2673 |
. . . . . . . 8
⊢ (𝑧 = 𝐶 → (𝐴 ∈ {𝑧, 𝐷} ↔ 𝐴 ∈ {𝐶, 𝐷})) |
22 | 19 | eleq2d 2673 |
. . . . . . . 8
⊢ (𝑧 = 𝐶 → (𝐵 ∈ {𝑧, 𝐷} ↔ 𝐵 ∈ {𝐶, 𝐷})) |
23 | 21, 22 | anbi12d 743 |
. . . . . . 7
⊢ (𝑧 = 𝐶 → ((𝐴 ∈ {𝑧, 𝐷} ∧ 𝐵 ∈ {𝑧, 𝐷}) ↔ (𝐴 ∈ {𝐶, 𝐷} ∧ 𝐵 ∈ {𝐶, 𝐷}))) |
24 | 20, 23 | bibi12d 334 |
. . . . . 6
⊢ (𝑧 = 𝐶 → (({𝐴, 𝐵} = {𝑧, 𝐷} ↔ (𝐴 ∈ {𝑧, 𝐷} ∧ 𝐵 ∈ {𝑧, 𝐷})) ↔ ({𝐴, 𝐵} = {𝐶, 𝐷} ↔ (𝐴 ∈ {𝐶, 𝐷} ∧ 𝐵 ∈ {𝐶, 𝐷})))) |
25 | 24 | imbi2d 329 |
. . . . 5
⊢ (𝑧 = 𝐶 → ((¬ 𝐴 = 𝐵 → ({𝐴, 𝐵} = {𝑧, 𝐷} ↔ (𝐴 ∈ {𝑧, 𝐷} ∧ 𝐵 ∈ {𝑧, 𝐷}))) ↔ (¬ 𝐴 = 𝐵 → ({𝐴, 𝐵} = {𝐶, 𝐷} ↔ (𝐴 ∈ {𝐶, 𝐷} ∧ 𝐵 ∈ {𝐶, 𝐷}))))) |
26 | 25 | imbi2d 329 |
. . . 4
⊢ (𝑧 = 𝐶 → ((𝐷 ∈ 𝑌 → (¬ 𝐴 = 𝐵 → ({𝐴, 𝐵} = {𝑧, 𝐷} ↔ (𝐴 ∈ {𝑧, 𝐷} ∧ 𝐵 ∈ {𝑧, 𝐷})))) ↔ (𝐷 ∈ 𝑌 → (¬ 𝐴 = 𝐵 → ({𝐴, 𝐵} = {𝐶, 𝐷} ↔ (𝐴 ∈ {𝐶, 𝐷} ∧ 𝐵 ∈ {𝐶, 𝐷})))))) |
27 | | preq2 4213 |
. . . . . . . . 9
⊢ (𝑤 = 𝐷 → {𝑧, 𝑤} = {𝑧, 𝐷}) |
28 | 27 | eqeq2d 2620 |
. . . . . . . 8
⊢ (𝑤 = 𝐷 → ({𝑥, 𝑦} = {𝑧, 𝑤} ↔ {𝑥, 𝑦} = {𝑧, 𝐷})) |
29 | 27 | eleq2d 2673 |
. . . . . . . . 9
⊢ (𝑤 = 𝐷 → (𝑥 ∈ {𝑧, 𝑤} ↔ 𝑥 ∈ {𝑧, 𝐷})) |
30 | 27 | eleq2d 2673 |
. . . . . . . . 9
⊢ (𝑤 = 𝐷 → (𝑦 ∈ {𝑧, 𝑤} ↔ 𝑦 ∈ {𝑧, 𝐷})) |
31 | 29, 30 | anbi12d 743 |
. . . . . . . 8
⊢ (𝑤 = 𝐷 → ((𝑥 ∈ {𝑧, 𝑤} ∧ 𝑦 ∈ {𝑧, 𝑤}) ↔ (𝑥 ∈ {𝑧, 𝐷} ∧ 𝑦 ∈ {𝑧, 𝐷}))) |
32 | 28, 31 | bibi12d 334 |
. . . . . . 7
⊢ (𝑤 = 𝐷 → (({𝑥, 𝑦} = {𝑧, 𝑤} ↔ (𝑥 ∈ {𝑧, 𝑤} ∧ 𝑦 ∈ {𝑧, 𝑤})) ↔ ({𝑥, 𝑦} = {𝑧, 𝐷} ↔ (𝑥 ∈ {𝑧, 𝐷} ∧ 𝑦 ∈ {𝑧, 𝐷})))) |
33 | 32 | imbi2d 329 |
. . . . . 6
⊢ (𝑤 = 𝐷 → ((¬ 𝑥 = 𝑦 → ({𝑥, 𝑦} = {𝑧, 𝑤} ↔ (𝑥 ∈ {𝑧, 𝑤} ∧ 𝑦 ∈ {𝑧, 𝑤}))) ↔ (¬ 𝑥 = 𝑦 → ({𝑥, 𝑦} = {𝑧, 𝐷} ↔ (𝑥 ∈ {𝑧, 𝐷} ∧ 𝑦 ∈ {𝑧, 𝐷}))))) |
34 | | vex 3176 |
. . . . . . 7
⊢ 𝑥 ∈ V |
35 | | vex 3176 |
. . . . . . 7
⊢ 𝑦 ∈ V |
36 | | vex 3176 |
. . . . . . 7
⊢ 𝑧 ∈ V |
37 | | vex 3176 |
. . . . . . 7
⊢ 𝑤 ∈ V |
38 | 34, 35, 36, 37 | prel12 4323 |
. . . . . 6
⊢ (¬
𝑥 = 𝑦 → ({𝑥, 𝑦} = {𝑧, 𝑤} ↔ (𝑥 ∈ {𝑧, 𝑤} ∧ 𝑦 ∈ {𝑧, 𝑤}))) |
39 | 33, 38 | vtoclg 3239 |
. . . . 5
⊢ (𝐷 ∈ 𝑌 → (¬ 𝑥 = 𝑦 → ({𝑥, 𝑦} = {𝑧, 𝐷} ↔ (𝑥 ∈ {𝑧, 𝐷} ∧ 𝑦 ∈ {𝑧, 𝐷})))) |
40 | 39 | a1i 11 |
. . . 4
⊢ ((𝑥 ∈ 𝑉 ∧ 𝑦 ∈ 𝑊 ∧ 𝑧 ∈ 𝑋) → (𝐷 ∈ 𝑌 → (¬ 𝑥 = 𝑦 → ({𝑥, 𝑦} = {𝑧, 𝐷} ↔ (𝑥 ∈ {𝑧, 𝐷} ∧ 𝑦 ∈ {𝑧, 𝐷}))))) |
41 | 9, 18, 26, 40 | vtocl3ga 3249 |
. . 3
⊢ ((𝐴 ∈ 𝑉 ∧ 𝐵 ∈ 𝑊 ∧ 𝐶 ∈ 𝑋) → (𝐷 ∈ 𝑌 → (¬ 𝐴 = 𝐵 → ({𝐴, 𝐵} = {𝐶, 𝐷} ↔ (𝐴 ∈ {𝐶, 𝐷} ∧ 𝐵 ∈ {𝐶, 𝐷}))))) |
42 | 41 | 3expa 1257 |
. 2
⊢ (((𝐴 ∈ 𝑉 ∧ 𝐵 ∈ 𝑊) ∧ 𝐶 ∈ 𝑋) → (𝐷 ∈ 𝑌 → (¬ 𝐴 = 𝐵 → ({𝐴, 𝐵} = {𝐶, 𝐷} ↔ (𝐴 ∈ {𝐶, 𝐷} ∧ 𝐵 ∈ {𝐶, 𝐷}))))) |
43 | 42 | impr 647 |
1
⊢ (((𝐴 ∈ 𝑉 ∧ 𝐵 ∈ 𝑊) ∧ (𝐶 ∈ 𝑋 ∧ 𝐷 ∈ 𝑌)) → (¬ 𝐴 = 𝐵 → ({𝐴, 𝐵} = {𝐶, 𝐷} ↔ (𝐴 ∈ {𝐶, 𝐷} ∧ 𝐵 ∈ {𝐶, 𝐷})))) |