| Step | Hyp | Ref
| Expression |
| 1 | | isdlat.b |
. . . 4
⊢ 𝐵 = (Base‘𝐾) |
| 2 | | isdlat.j |
. . . 4
⊢ ∨ =
(join‘𝐾) |
| 3 | | isdlat.m |
. . . 4
⊢ ∧ =
(meet‘𝐾) |
| 4 | 1, 2, 3 | isdlat 18537 |
. . 3
⊢ (𝐾 ∈ DLat ↔ (𝐾 ∈ Lat ∧ ∀𝑥 ∈ 𝐵 ∀𝑦 ∈ 𝐵 ∀𝑧 ∈ 𝐵 (𝑥 ∧ (𝑦 ∨ 𝑧)) = ((𝑥 ∧ 𝑦) ∨ (𝑥 ∧ 𝑧)))) |
| 5 | 4 | simprbi 496 |
. 2
⊢ (𝐾 ∈ DLat →
∀𝑥 ∈ 𝐵 ∀𝑦 ∈ 𝐵 ∀𝑧 ∈ 𝐵 (𝑥 ∧ (𝑦 ∨ 𝑧)) = ((𝑥 ∧ 𝑦) ∨ (𝑥 ∧ 𝑧))) |
| 6 | | oveq1 7417 |
. . . 4
⊢ (𝑥 = 𝑋 → (𝑥 ∧ (𝑦 ∨ 𝑧)) = (𝑋 ∧ (𝑦 ∨ 𝑧))) |
| 7 | | oveq1 7417 |
. . . . 5
⊢ (𝑥 = 𝑋 → (𝑥 ∧ 𝑦) = (𝑋 ∧ 𝑦)) |
| 8 | | oveq1 7417 |
. . . . 5
⊢ (𝑥 = 𝑋 → (𝑥 ∧ 𝑧) = (𝑋 ∧ 𝑧)) |
| 9 | 7, 8 | oveq12d 7428 |
. . . 4
⊢ (𝑥 = 𝑋 → ((𝑥 ∧ 𝑦) ∨ (𝑥 ∧ 𝑧)) = ((𝑋 ∧ 𝑦) ∨ (𝑋 ∧ 𝑧))) |
| 10 | 6, 9 | eqeq12d 2752 |
. . 3
⊢ (𝑥 = 𝑋 → ((𝑥 ∧ (𝑦 ∨ 𝑧)) = ((𝑥 ∧ 𝑦) ∨ (𝑥 ∧ 𝑧)) ↔ (𝑋 ∧ (𝑦 ∨ 𝑧)) = ((𝑋 ∧ 𝑦) ∨ (𝑋 ∧ 𝑧)))) |
| 11 | | oveq1 7417 |
. . . . 5
⊢ (𝑦 = 𝑌 → (𝑦 ∨ 𝑧) = (𝑌 ∨ 𝑧)) |
| 12 | 11 | oveq2d 7426 |
. . . 4
⊢ (𝑦 = 𝑌 → (𝑋 ∧ (𝑦 ∨ 𝑧)) = (𝑋 ∧ (𝑌 ∨ 𝑧))) |
| 13 | | oveq2 7418 |
. . . . 5
⊢ (𝑦 = 𝑌 → (𝑋 ∧ 𝑦) = (𝑋 ∧ 𝑌)) |
| 14 | 13 | oveq1d 7425 |
. . . 4
⊢ (𝑦 = 𝑌 → ((𝑋 ∧ 𝑦) ∨ (𝑋 ∧ 𝑧)) = ((𝑋 ∧ 𝑌) ∨ (𝑋 ∧ 𝑧))) |
| 15 | 12, 14 | eqeq12d 2752 |
. . 3
⊢ (𝑦 = 𝑌 → ((𝑋 ∧ (𝑦 ∨ 𝑧)) = ((𝑋 ∧ 𝑦) ∨ (𝑋 ∧ 𝑧)) ↔ (𝑋 ∧ (𝑌 ∨ 𝑧)) = ((𝑋 ∧ 𝑌) ∨ (𝑋 ∧ 𝑧)))) |
| 16 | | oveq2 7418 |
. . . . 5
⊢ (𝑧 = 𝑍 → (𝑌 ∨ 𝑧) = (𝑌 ∨ 𝑍)) |
| 17 | 16 | oveq2d 7426 |
. . . 4
⊢ (𝑧 = 𝑍 → (𝑋 ∧ (𝑌 ∨ 𝑧)) = (𝑋 ∧ (𝑌 ∨ 𝑍))) |
| 18 | | oveq2 7418 |
. . . . 5
⊢ (𝑧 = 𝑍 → (𝑋 ∧ 𝑧) = (𝑋 ∧ 𝑍)) |
| 19 | 18 | oveq2d 7426 |
. . . 4
⊢ (𝑧 = 𝑍 → ((𝑋 ∧ 𝑌) ∨ (𝑋 ∧ 𝑧)) = ((𝑋 ∧ 𝑌) ∨ (𝑋 ∧ 𝑍))) |
| 20 | 17, 19 | eqeq12d 2752 |
. . 3
⊢ (𝑧 = 𝑍 → ((𝑋 ∧ (𝑌 ∨ 𝑧)) = ((𝑋 ∧ 𝑌) ∨ (𝑋 ∧ 𝑧)) ↔ (𝑋 ∧ (𝑌 ∨ 𝑍)) = ((𝑋 ∧ 𝑌) ∨ (𝑋 ∧ 𝑍)))) |
| 21 | 10, 15, 20 | rspc3v 3622 |
. 2
⊢ ((𝑋 ∈ 𝐵 ∧ 𝑌 ∈ 𝐵 ∧ 𝑍 ∈ 𝐵) → (∀𝑥 ∈ 𝐵 ∀𝑦 ∈ 𝐵 ∀𝑧 ∈ 𝐵 (𝑥 ∧ (𝑦 ∨ 𝑧)) = ((𝑥 ∧ 𝑦) ∨ (𝑥 ∧ 𝑧)) → (𝑋 ∧ (𝑌 ∨ 𝑍)) = ((𝑋 ∧ 𝑌) ∨ (𝑋 ∧ 𝑍)))) |
| 22 | 5, 21 | mpan9 506 |
1
⊢ ((𝐾 ∈ DLat ∧ (𝑋 ∈ 𝐵 ∧ 𝑌 ∈ 𝐵 ∧ 𝑍 ∈ 𝐵)) → (𝑋 ∧ (𝑌 ∨ 𝑍)) = ((𝑋 ∧ 𝑌) ∨ (𝑋 ∧ 𝑍))) |