Proof of Theorem prneimg2
Step | Hyp | Ref
| Expression |
1 | | preq12bg 4878 |
. . 3
⊢ (((𝐴 ∈ 𝑈 ∧ 𝐵 ∈ 𝑉) ∧ (𝐶 ∈ 𝑋 ∧ 𝐷 ∈ 𝑌)) → ({𝐴, 𝐵} = {𝐶, 𝐷} ↔ ((𝐴 = 𝐶 ∧ 𝐵 = 𝐷) ∨ (𝐴 = 𝐷 ∧ 𝐵 = 𝐶)))) |
2 | 1 | necon3abid 2983 |
. 2
⊢ (((𝐴 ∈ 𝑈 ∧ 𝐵 ∈ 𝑉) ∧ (𝐶 ∈ 𝑋 ∧ 𝐷 ∈ 𝑌)) → ({𝐴, 𝐵} ≠ {𝐶, 𝐷} ↔ ¬ ((𝐴 = 𝐶 ∧ 𝐵 = 𝐷) ∨ (𝐴 = 𝐷 ∧ 𝐵 = 𝐶)))) |
3 | | ioran 984 |
. . 3
⊢ (¬
((𝐴 = 𝐶 ∧ 𝐵 = 𝐷) ∨ (𝐴 = 𝐷 ∧ 𝐵 = 𝐶)) ↔ (¬ (𝐴 = 𝐶 ∧ 𝐵 = 𝐷) ∧ ¬ (𝐴 = 𝐷 ∧ 𝐵 = 𝐶))) |
4 | | ianor 982 |
. . . . 5
⊢ (¬
(𝐴 = 𝐶 ∧ 𝐵 = 𝐷) ↔ (¬ 𝐴 = 𝐶 ∨ ¬ 𝐵 = 𝐷)) |
5 | | df-ne 2947 |
. . . . . 6
⊢ (𝐴 ≠ 𝐶 ↔ ¬ 𝐴 = 𝐶) |
6 | | df-ne 2947 |
. . . . . 6
⊢ (𝐵 ≠ 𝐷 ↔ ¬ 𝐵 = 𝐷) |
7 | 5, 6 | orbi12i 913 |
. . . . 5
⊢ ((𝐴 ≠ 𝐶 ∨ 𝐵 ≠ 𝐷) ↔ (¬ 𝐴 = 𝐶 ∨ ¬ 𝐵 = 𝐷)) |
8 | 4, 7 | bitr4i 278 |
. . . 4
⊢ (¬
(𝐴 = 𝐶 ∧ 𝐵 = 𝐷) ↔ (𝐴 ≠ 𝐶 ∨ 𝐵 ≠ 𝐷)) |
9 | | ianor 982 |
. . . . 5
⊢ (¬
(𝐴 = 𝐷 ∧ 𝐵 = 𝐶) ↔ (¬ 𝐴 = 𝐷 ∨ ¬ 𝐵 = 𝐶)) |
10 | | df-ne 2947 |
. . . . . 6
⊢ (𝐴 ≠ 𝐷 ↔ ¬ 𝐴 = 𝐷) |
11 | | df-ne 2947 |
. . . . . 6
⊢ (𝐵 ≠ 𝐶 ↔ ¬ 𝐵 = 𝐶) |
12 | 10, 11 | orbi12i 913 |
. . . . 5
⊢ ((𝐴 ≠ 𝐷 ∨ 𝐵 ≠ 𝐶) ↔ (¬ 𝐴 = 𝐷 ∨ ¬ 𝐵 = 𝐶)) |
13 | 9, 12 | bitr4i 278 |
. . . 4
⊢ (¬
(𝐴 = 𝐷 ∧ 𝐵 = 𝐶) ↔ (𝐴 ≠ 𝐷 ∨ 𝐵 ≠ 𝐶)) |
14 | 8, 13 | anbi12i 627 |
. . 3
⊢ ((¬
(𝐴 = 𝐶 ∧ 𝐵 = 𝐷) ∧ ¬ (𝐴 = 𝐷 ∧ 𝐵 = 𝐶)) ↔ ((𝐴 ≠ 𝐶 ∨ 𝐵 ≠ 𝐷) ∧ (𝐴 ≠ 𝐷 ∨ 𝐵 ≠ 𝐶))) |
15 | 3, 14 | bitri 275 |
. 2
⊢ (¬
((𝐴 = 𝐶 ∧ 𝐵 = 𝐷) ∨ (𝐴 = 𝐷 ∧ 𝐵 = 𝐶)) ↔ ((𝐴 ≠ 𝐶 ∨ 𝐵 ≠ 𝐷) ∧ (𝐴 ≠ 𝐷 ∨ 𝐵 ≠ 𝐶))) |
16 | 2, 15 | bitrdi 287 |
1
⊢ (((𝐴 ∈ 𝑈 ∧ 𝐵 ∈ 𝑉) ∧ (𝐶 ∈ 𝑋 ∧ 𝐷 ∈ 𝑌)) → ({𝐴, 𝐵} ≠ {𝐶, 𝐷} ↔ ((𝐴 ≠ 𝐶 ∨ 𝐵 ≠ 𝐷) ∧ (𝐴 ≠ 𝐷 ∨ 𝐵 ≠ 𝐶)))) |