Step |
Hyp |
Ref |
Expression |
1 |
|
hlatjcom.j |
⊢ ∨ = ( join ‘ 𝐾 ) |
2 |
|
hlatjcom.a |
⊢ 𝐴 = ( Atoms ‘ 𝐾 ) |
3 |
1 2
|
hlatj32 |
⊢ ( ( 𝐾 ∈ HL ∧ ( 𝑃 ∈ 𝐴 ∧ 𝑄 ∈ 𝐴 ∧ 𝑅 ∈ 𝐴 ) ) → ( ( 𝑃 ∨ 𝑄 ) ∨ 𝑅 ) = ( ( 𝑃 ∨ 𝑅 ) ∨ 𝑄 ) ) |
4 |
1 2
|
hlatjcom |
⊢ ( ( 𝐾 ∈ HL ∧ 𝑃 ∈ 𝐴 ∧ 𝑅 ∈ 𝐴 ) → ( 𝑃 ∨ 𝑅 ) = ( 𝑅 ∨ 𝑃 ) ) |
5 |
4
|
3adant3r2 |
⊢ ( ( 𝐾 ∈ HL ∧ ( 𝑃 ∈ 𝐴 ∧ 𝑄 ∈ 𝐴 ∧ 𝑅 ∈ 𝐴 ) ) → ( 𝑃 ∨ 𝑅 ) = ( 𝑅 ∨ 𝑃 ) ) |
6 |
5
|
oveq1d |
⊢ ( ( 𝐾 ∈ HL ∧ ( 𝑃 ∈ 𝐴 ∧ 𝑄 ∈ 𝐴 ∧ 𝑅 ∈ 𝐴 ) ) → ( ( 𝑃 ∨ 𝑅 ) ∨ 𝑄 ) = ( ( 𝑅 ∨ 𝑃 ) ∨ 𝑄 ) ) |
7 |
3 6
|
eqtrd |
⊢ ( ( 𝐾 ∈ HL ∧ ( 𝑃 ∈ 𝐴 ∧ 𝑄 ∈ 𝐴 ∧ 𝑅 ∈ 𝐴 ) ) → ( ( 𝑃 ∨ 𝑄 ) ∨ 𝑅 ) = ( ( 𝑅 ∨ 𝑃 ) ∨ 𝑄 ) ) |