Proof of Theorem cdleme27b
Step | Hyp | Ref
| Expression |
1 | | breq1 5073 |
. . 3
⊢ (𝑠 = 𝑡 → (𝑠 ≤ (𝑃 ∨ 𝑄) ↔ 𝑡 ≤ (𝑃 ∨ 𝑄))) |
2 | | oveq1 7262 |
. . . . . . . . . . . 12
⊢ (𝑠 = 𝑡 → (𝑠 ∨ 𝑧) = (𝑡 ∨ 𝑧)) |
3 | 2 | oveq1d 7270 |
. . . . . . . . . . 11
⊢ (𝑠 = 𝑡 → ((𝑠 ∨ 𝑧) ∧ 𝑊) = ((𝑡 ∨ 𝑧) ∧ 𝑊)) |
4 | 3 | oveq2d 7271 |
. . . . . . . . . 10
⊢ (𝑠 = 𝑡 → (𝑍 ∨ ((𝑠 ∨ 𝑧) ∧ 𝑊)) = (𝑍 ∨ ((𝑡 ∨ 𝑧) ∧ 𝑊))) |
5 | 4 | oveq2d 7271 |
. . . . . . . . 9
⊢ (𝑠 = 𝑡 → ((𝑃 ∨ 𝑄) ∧ (𝑍 ∨ ((𝑠 ∨ 𝑧) ∧ 𝑊))) = ((𝑃 ∨ 𝑄) ∧ (𝑍 ∨ ((𝑡 ∨ 𝑧) ∧ 𝑊)))) |
6 | | cdleme27.n |
. . . . . . . . 9
⊢ 𝑁 = ((𝑃 ∨ 𝑄) ∧ (𝑍 ∨ ((𝑠 ∨ 𝑧) ∧ 𝑊))) |
7 | | cdleme27.o |
. . . . . . . . 9
⊢ 𝑂 = ((𝑃 ∨ 𝑄) ∧ (𝑍 ∨ ((𝑡 ∨ 𝑧) ∧ 𝑊))) |
8 | 5, 6, 7 | 3eqtr4g 2804 |
. . . . . . . 8
⊢ (𝑠 = 𝑡 → 𝑁 = 𝑂) |
9 | 8 | eqeq2d 2749 |
. . . . . . 7
⊢ (𝑠 = 𝑡 → (𝑢 = 𝑁 ↔ 𝑢 = 𝑂)) |
10 | 9 | imbi2d 340 |
. . . . . 6
⊢ (𝑠 = 𝑡 → (((¬ 𝑧 ≤ 𝑊 ∧ ¬ 𝑧 ≤ (𝑃 ∨ 𝑄)) → 𝑢 = 𝑁) ↔ ((¬ 𝑧 ≤ 𝑊 ∧ ¬ 𝑧 ≤ (𝑃 ∨ 𝑄)) → 𝑢 = 𝑂))) |
11 | 10 | ralbidv 3120 |
. . . . 5
⊢ (𝑠 = 𝑡 → (∀𝑧 ∈ 𝐴 ((¬ 𝑧 ≤ 𝑊 ∧ ¬ 𝑧 ≤ (𝑃 ∨ 𝑄)) → 𝑢 = 𝑁) ↔ ∀𝑧 ∈ 𝐴 ((¬ 𝑧 ≤ 𝑊 ∧ ¬ 𝑧 ≤ (𝑃 ∨ 𝑄)) → 𝑢 = 𝑂))) |
12 | 11 | riotabidv 7214 |
. . . 4
⊢ (𝑠 = 𝑡 → (℩𝑢 ∈ 𝐵 ∀𝑧 ∈ 𝐴 ((¬ 𝑧 ≤ 𝑊 ∧ ¬ 𝑧 ≤ (𝑃 ∨ 𝑄)) → 𝑢 = 𝑁)) = (℩𝑢 ∈ 𝐵 ∀𝑧 ∈ 𝐴 ((¬ 𝑧 ≤ 𝑊 ∧ ¬ 𝑧 ≤ (𝑃 ∨ 𝑄)) → 𝑢 = 𝑂))) |
13 | | cdleme27.d |
. . . 4
⊢ 𝐷 = (℩𝑢 ∈ 𝐵 ∀𝑧 ∈ 𝐴 ((¬ 𝑧 ≤ 𝑊 ∧ ¬ 𝑧 ≤ (𝑃 ∨ 𝑄)) → 𝑢 = 𝑁)) |
14 | | cdleme27.e |
. . . 4
⊢ 𝐸 = (℩𝑢 ∈ 𝐵 ∀𝑧 ∈ 𝐴 ((¬ 𝑧 ≤ 𝑊 ∧ ¬ 𝑧 ≤ (𝑃 ∨ 𝑄)) → 𝑢 = 𝑂)) |
15 | 12, 13, 14 | 3eqtr4g 2804 |
. . 3
⊢ (𝑠 = 𝑡 → 𝐷 = 𝐸) |
16 | | oveq1 7262 |
. . . . 5
⊢ (𝑠 = 𝑡 → (𝑠 ∨ 𝑈) = (𝑡 ∨ 𝑈)) |
17 | | oveq2 7263 |
. . . . . . 7
⊢ (𝑠 = 𝑡 → (𝑃 ∨ 𝑠) = (𝑃 ∨ 𝑡)) |
18 | 17 | oveq1d 7270 |
. . . . . 6
⊢ (𝑠 = 𝑡 → ((𝑃 ∨ 𝑠) ∧ 𝑊) = ((𝑃 ∨ 𝑡) ∧ 𝑊)) |
19 | 18 | oveq2d 7271 |
. . . . 5
⊢ (𝑠 = 𝑡 → (𝑄 ∨ ((𝑃 ∨ 𝑠) ∧ 𝑊)) = (𝑄 ∨ ((𝑃 ∨ 𝑡) ∧ 𝑊))) |
20 | 16, 19 | oveq12d 7273 |
. . . 4
⊢ (𝑠 = 𝑡 → ((𝑠 ∨ 𝑈) ∧ (𝑄 ∨ ((𝑃 ∨ 𝑠) ∧ 𝑊))) = ((𝑡 ∨ 𝑈) ∧ (𝑄 ∨ ((𝑃 ∨ 𝑡) ∧ 𝑊)))) |
21 | | cdleme27.f |
. . . 4
⊢ 𝐹 = ((𝑠 ∨ 𝑈) ∧ (𝑄 ∨ ((𝑃 ∨ 𝑠) ∧ 𝑊))) |
22 | | cdleme27.g |
. . . 4
⊢ 𝐺 = ((𝑡 ∨ 𝑈) ∧ (𝑄 ∨ ((𝑃 ∨ 𝑡) ∧ 𝑊))) |
23 | 20, 21, 22 | 3eqtr4g 2804 |
. . 3
⊢ (𝑠 = 𝑡 → 𝐹 = 𝐺) |
24 | 1, 15, 23 | ifbieq12d 4484 |
. 2
⊢ (𝑠 = 𝑡 → if(𝑠 ≤ (𝑃 ∨ 𝑄), 𝐷, 𝐹) = if(𝑡 ≤ (𝑃 ∨ 𝑄), 𝐸, 𝐺)) |
25 | | cdleme27.c |
. 2
⊢ 𝐶 = if(𝑠 ≤ (𝑃 ∨ 𝑄), 𝐷, 𝐹) |
26 | | cdleme27.y |
. 2
⊢ 𝑌 = if(𝑡 ≤ (𝑃 ∨ 𝑄), 𝐸, 𝐺) |
27 | 24, 25, 26 | 3eqtr4g 2804 |
1
⊢ (𝑠 = 𝑡 → 𝐶 = 𝑌) |