Proof of Theorem f1omvdco3
Step | Hyp | Ref
| Expression |
1 | | notbi 318 |
. . . . 5
⊢ ((𝑋 ∈ dom (𝐹 ∖ I ) ↔ 𝑋 ∈ dom (𝐺 ∖ I )) ↔ (¬ 𝑋 ∈ dom (𝐹 ∖ I ) ↔ ¬ 𝑋 ∈ dom (𝐺 ∖ I ))) |
2 | | disjsn 4644 |
. . . . . . 7
⊢ ((dom
(𝐹 ∖ I ) ∩ {𝑋}) = ∅ ↔ ¬ 𝑋 ∈ dom (𝐹 ∖ I )) |
3 | | disj2 4388 |
. . . . . . 7
⊢ ((dom
(𝐹 ∖ I ) ∩ {𝑋}) = ∅ ↔ dom (𝐹 ∖ I ) ⊆ (V ∖
{𝑋})) |
4 | 2, 3 | bitr3i 276 |
. . . . . 6
⊢ (¬
𝑋 ∈ dom (𝐹 ∖ I ) ↔ dom (𝐹 ∖ I ) ⊆ (V ∖
{𝑋})) |
5 | | disjsn 4644 |
. . . . . . 7
⊢ ((dom
(𝐺 ∖ I ) ∩ {𝑋}) = ∅ ↔ ¬ 𝑋 ∈ dom (𝐺 ∖ I )) |
6 | | disj2 4388 |
. . . . . . 7
⊢ ((dom
(𝐺 ∖ I ) ∩ {𝑋}) = ∅ ↔ dom (𝐺 ∖ I ) ⊆ (V ∖
{𝑋})) |
7 | 5, 6 | bitr3i 276 |
. . . . . 6
⊢ (¬
𝑋 ∈ dom (𝐺 ∖ I ) ↔ dom (𝐺 ∖ I ) ⊆ (V ∖
{𝑋})) |
8 | 4, 7 | bibi12i 339 |
. . . . 5
⊢ ((¬
𝑋 ∈ dom (𝐹 ∖ I ) ↔ ¬ 𝑋 ∈ dom (𝐺 ∖ I )) ↔ (dom (𝐹 ∖ I ) ⊆ (V ∖ {𝑋}) ↔ dom (𝐺 ∖ I ) ⊆ (V ∖ {𝑋}))) |
9 | 1, 8 | bitri 274 |
. . . 4
⊢ ((𝑋 ∈ dom (𝐹 ∖ I ) ↔ 𝑋 ∈ dom (𝐺 ∖ I )) ↔ (dom (𝐹 ∖ I ) ⊆ (V ∖ {𝑋}) ↔ dom (𝐺 ∖ I ) ⊆ (V ∖ {𝑋}))) |
10 | 9 | notbii 319 |
. . 3
⊢ (¬
(𝑋 ∈ dom (𝐹 ∖ I ) ↔ 𝑋 ∈ dom (𝐺 ∖ I )) ↔ ¬ (dom (𝐹 ∖ I ) ⊆ (V ∖
{𝑋}) ↔ dom (𝐺 ∖ I ) ⊆ (V ∖
{𝑋}))) |
11 | | df-xor 1504 |
. . 3
⊢ ((𝑋 ∈ dom (𝐹 ∖ I ) ⊻ 𝑋 ∈ dom (𝐺 ∖ I )) ↔ ¬ (𝑋 ∈ dom (𝐹 ∖ I ) ↔ 𝑋 ∈ dom (𝐺 ∖ I ))) |
12 | | df-xor 1504 |
. . 3
⊢ ((dom
(𝐹 ∖ I ) ⊆ (V
∖ {𝑋}) ⊻ dom
(𝐺 ∖ I ) ⊆ (V
∖ {𝑋})) ↔ ¬
(dom (𝐹 ∖ I ) ⊆
(V ∖ {𝑋}) ↔ dom
(𝐺 ∖ I ) ⊆ (V
∖ {𝑋}))) |
13 | 10, 11, 12 | 3bitr4i 302 |
. 2
⊢ ((𝑋 ∈ dom (𝐹 ∖ I ) ⊻ 𝑋 ∈ dom (𝐺 ∖ I )) ↔ (dom (𝐹 ∖ I ) ⊆ (V ∖ {𝑋}) ⊻ dom (𝐺 ∖ I ) ⊆ (V ∖
{𝑋}))) |
14 | | f1omvdco2 18971 |
. . 3
⊢ ((𝐹:𝐴–1-1-onto→𝐴 ∧ 𝐺:𝐴–1-1-onto→𝐴 ∧ (dom (𝐹 ∖ I ) ⊆ (V ∖ {𝑋}) ⊻ dom (𝐺 ∖ I ) ⊆ (V ∖
{𝑋}))) → ¬ dom
((𝐹 ∘ 𝐺) ∖ I ) ⊆ (V ∖
{𝑋})) |
15 | | disj2 4388 |
. . . . 5
⊢ ((dom
((𝐹 ∘ 𝐺) ∖ I ) ∩ {𝑋}) = ∅ ↔ dom ((𝐹 ∘ 𝐺) ∖ I ) ⊆ (V ∖ {𝑋})) |
16 | | disjsn 4644 |
. . . . 5
⊢ ((dom
((𝐹 ∘ 𝐺) ∖ I ) ∩ {𝑋}) = ∅ ↔ ¬ 𝑋 ∈ dom ((𝐹 ∘ 𝐺) ∖ I )) |
17 | 15, 16 | bitr3i 276 |
. . . 4
⊢ (dom
((𝐹 ∘ 𝐺) ∖ I ) ⊆ (V ∖
{𝑋}) ↔ ¬ 𝑋 ∈ dom ((𝐹 ∘ 𝐺) ∖ I )) |
18 | 17 | con2bii 357 |
. . 3
⊢ (𝑋 ∈ dom ((𝐹 ∘ 𝐺) ∖ I ) ↔ ¬ dom ((𝐹 ∘ 𝐺) ∖ I ) ⊆ (V ∖ {𝑋})) |
19 | 14, 18 | sylibr 233 |
. 2
⊢ ((𝐹:𝐴–1-1-onto→𝐴 ∧ 𝐺:𝐴–1-1-onto→𝐴 ∧ (dom (𝐹 ∖ I ) ⊆ (V ∖ {𝑋}) ⊻ dom (𝐺 ∖ I ) ⊆ (V ∖
{𝑋}))) → 𝑋 ∈ dom ((𝐹 ∘ 𝐺) ∖ I )) |
20 | 13, 19 | syl3an3b 1403 |
1
⊢ ((𝐹:𝐴–1-1-onto→𝐴 ∧ 𝐺:𝐴–1-1-onto→𝐴 ∧ (𝑋 ∈ dom (𝐹 ∖ I ) ⊻ 𝑋 ∈ dom (𝐺 ∖ I ))) → 𝑋 ∈ dom ((𝐹 ∘ 𝐺) ∖ I )) |