Proof of Theorem ecovass
| Step | Hyp | Ref
 | Expression | 
| 1 |   | ecovass.1 | 
. 2
⊢ 𝐷 = ((𝑆 × 𝑆) / ∼ ) | 
| 2 |   | oveq1 5929 | 
. . . 4
⊢
([〈𝑥, 𝑦〉] ∼ = 𝐴 → ([〈𝑥, 𝑦〉] ∼ + [〈𝑧, 𝑤〉] ∼ ) = (𝐴 + [〈𝑧, 𝑤〉] ∼ )) | 
| 3 | 2 | oveq1d 5937 | 
. . 3
⊢
([〈𝑥, 𝑦〉] ∼ = 𝐴 → (([〈𝑥, 𝑦〉] ∼ + [〈𝑧, 𝑤〉] ∼ ) + [〈𝑣, 𝑢〉] ∼ ) = ((𝐴 + [〈𝑧, 𝑤〉] ∼ ) + [〈𝑣, 𝑢〉] ∼ )) | 
| 4 |   | oveq1 5929 | 
. . 3
⊢
([〈𝑥, 𝑦〉] ∼ = 𝐴 → ([〈𝑥, 𝑦〉] ∼ + ([〈𝑧, 𝑤〉] ∼ + [〈𝑣, 𝑢〉] ∼ )) = (𝐴 + ([〈𝑧, 𝑤〉] ∼ + [〈𝑣, 𝑢〉] ∼
))) | 
| 5 | 3, 4 | eqeq12d 2211 | 
. 2
⊢
([〈𝑥, 𝑦〉] ∼ = 𝐴 → ((([〈𝑥, 𝑦〉] ∼ + [〈𝑧, 𝑤〉] ∼ ) + [〈𝑣, 𝑢〉] ∼ ) = ([〈𝑥, 𝑦〉] ∼ + ([〈𝑧, 𝑤〉] ∼ + [〈𝑣, 𝑢〉] ∼ )) ↔ ((𝐴 + [〈𝑧, 𝑤〉] ∼ ) + [〈𝑣, 𝑢〉] ∼ ) = (𝐴 + ([〈𝑧, 𝑤〉] ∼ + [〈𝑣, 𝑢〉] ∼
)))) | 
| 6 |   | oveq2 5930 | 
. . . 4
⊢
([〈𝑧, 𝑤〉] ∼ = 𝐵 → (𝐴 + [〈𝑧, 𝑤〉] ∼ ) = (𝐴 + 𝐵)) | 
| 7 | 6 | oveq1d 5937 | 
. . 3
⊢
([〈𝑧, 𝑤〉] ∼ = 𝐵 → ((𝐴 + [〈𝑧, 𝑤〉] ∼ ) + [〈𝑣, 𝑢〉] ∼ ) = ((𝐴 + 𝐵) + [〈𝑣, 𝑢〉] ∼ )) | 
| 8 |   | oveq1 5929 | 
. . . 4
⊢
([〈𝑧, 𝑤〉] ∼ = 𝐵 → ([〈𝑧, 𝑤〉] ∼ + [〈𝑣, 𝑢〉] ∼ ) = (𝐵 + [〈𝑣, 𝑢〉] ∼ )) | 
| 9 | 8 | oveq2d 5938 | 
. . 3
⊢
([〈𝑧, 𝑤〉] ∼ = 𝐵 → (𝐴 + ([〈𝑧, 𝑤〉] ∼ + [〈𝑣, 𝑢〉] ∼ )) = (𝐴 + (𝐵 + [〈𝑣, 𝑢〉] ∼
))) | 
| 10 | 7, 9 | eqeq12d 2211 | 
. 2
⊢
([〈𝑧, 𝑤〉] ∼ = 𝐵 → (((𝐴 + [〈𝑧, 𝑤〉] ∼ ) + [〈𝑣, 𝑢〉] ∼ ) = (𝐴 + ([〈𝑧, 𝑤〉] ∼ + [〈𝑣, 𝑢〉] ∼ )) ↔ ((𝐴 + 𝐵) + [〈𝑣, 𝑢〉] ∼ ) = (𝐴 + (𝐵 + [〈𝑣, 𝑢〉] ∼
)))) | 
| 11 |   | oveq2 5930 | 
. . 3
⊢
([〈𝑣, 𝑢〉] ∼ = 𝐶 → ((𝐴 + 𝐵) + [〈𝑣, 𝑢〉] ∼ ) = ((𝐴 + 𝐵) + 𝐶)) | 
| 12 |   | oveq2 5930 | 
. . . 4
⊢
([〈𝑣, 𝑢〉] ∼ = 𝐶 → (𝐵 + [〈𝑣, 𝑢〉] ∼ ) = (𝐵 + 𝐶)) | 
| 13 | 12 | oveq2d 5938 | 
. . 3
⊢
([〈𝑣, 𝑢〉] ∼ = 𝐶 → (𝐴 + (𝐵 + [〈𝑣, 𝑢〉] ∼ )) = (𝐴 + (𝐵 + 𝐶))) | 
| 14 | 11, 13 | eqeq12d 2211 | 
. 2
⊢
([〈𝑣, 𝑢〉] ∼ = 𝐶 → (((𝐴 + 𝐵) + [〈𝑣, 𝑢〉] ∼ ) = (𝐴 + (𝐵 + [〈𝑣, 𝑢〉] ∼ )) ↔ ((𝐴 + 𝐵) + 𝐶) = (𝐴 + (𝐵 + 𝐶)))) | 
| 15 |   | ecovass.8 | 
. . . 4
⊢ 𝐽 = 𝐿 | 
| 16 |   | ecovass.9 | 
. . . 4
⊢ 𝐾 = 𝑀 | 
| 17 |   | opeq12 3810 | 
. . . . 5
⊢ ((𝐽 = 𝐿 ∧ 𝐾 = 𝑀) → 〈𝐽, 𝐾〉 = 〈𝐿, 𝑀〉) | 
| 18 | 17 | eceq1d 6628 | 
. . . 4
⊢ ((𝐽 = 𝐿 ∧ 𝐾 = 𝑀) → [〈𝐽, 𝐾〉] ∼ = [〈𝐿, 𝑀〉] ∼ ) | 
| 19 | 15, 16, 18 | mp2an 426 | 
. . 3
⊢
[〈𝐽, 𝐾〉] ∼ = [〈𝐿, 𝑀〉] ∼ | 
| 20 |   | ecovass.2 | 
. . . . . . 7
⊢ (((𝑥 ∈ 𝑆 ∧ 𝑦 ∈ 𝑆) ∧ (𝑧 ∈ 𝑆 ∧ 𝑤 ∈ 𝑆)) → ([〈𝑥, 𝑦〉] ∼ + [〈𝑧, 𝑤〉] ∼ ) = [〈𝐺, 𝐻〉] ∼ ) | 
| 21 | 20 | oveq1d 5937 | 
. . . . . 6
⊢ (((𝑥 ∈ 𝑆 ∧ 𝑦 ∈ 𝑆) ∧ (𝑧 ∈ 𝑆 ∧ 𝑤 ∈ 𝑆)) → (([〈𝑥, 𝑦〉] ∼ + [〈𝑧, 𝑤〉] ∼ ) + [〈𝑣, 𝑢〉] ∼ ) = ([〈𝐺, 𝐻〉] ∼ + [〈𝑣, 𝑢〉] ∼ )) | 
| 22 | 21 | adantr 276 | 
. . . . 5
⊢ ((((𝑥 ∈ 𝑆 ∧ 𝑦 ∈ 𝑆) ∧ (𝑧 ∈ 𝑆 ∧ 𝑤 ∈ 𝑆)) ∧ (𝑣 ∈ 𝑆 ∧ 𝑢 ∈ 𝑆)) → (([〈𝑥, 𝑦〉] ∼ + [〈𝑧, 𝑤〉] ∼ ) + [〈𝑣, 𝑢〉] ∼ ) = ([〈𝐺, 𝐻〉] ∼ + [〈𝑣, 𝑢〉] ∼ )) | 
| 23 |   | ecovass.6 | 
. . . . . 6
⊢ (((𝑥 ∈ 𝑆 ∧ 𝑦 ∈ 𝑆) ∧ (𝑧 ∈ 𝑆 ∧ 𝑤 ∈ 𝑆)) → (𝐺 ∈ 𝑆 ∧ 𝐻 ∈ 𝑆)) | 
| 24 |   | ecovass.4 | 
. . . . . 6
⊢ (((𝐺 ∈ 𝑆 ∧ 𝐻 ∈ 𝑆) ∧ (𝑣 ∈ 𝑆 ∧ 𝑢 ∈ 𝑆)) → ([〈𝐺, 𝐻〉] ∼ + [〈𝑣, 𝑢〉] ∼ ) = [〈𝐽, 𝐾〉] ∼ ) | 
| 25 | 23, 24 | sylan 283 | 
. . . . 5
⊢ ((((𝑥 ∈ 𝑆 ∧ 𝑦 ∈ 𝑆) ∧ (𝑧 ∈ 𝑆 ∧ 𝑤 ∈ 𝑆)) ∧ (𝑣 ∈ 𝑆 ∧ 𝑢 ∈ 𝑆)) → ([〈𝐺, 𝐻〉] ∼ + [〈𝑣, 𝑢〉] ∼ ) = [〈𝐽, 𝐾〉] ∼ ) | 
| 26 | 22, 25 | eqtrd 2229 | 
. . . 4
⊢ ((((𝑥 ∈ 𝑆 ∧ 𝑦 ∈ 𝑆) ∧ (𝑧 ∈ 𝑆 ∧ 𝑤 ∈ 𝑆)) ∧ (𝑣 ∈ 𝑆 ∧ 𝑢 ∈ 𝑆)) → (([〈𝑥, 𝑦〉] ∼ + [〈𝑧, 𝑤〉] ∼ ) + [〈𝑣, 𝑢〉] ∼ ) = [〈𝐽, 𝐾〉] ∼ ) | 
| 27 | 26 | 3impa 1196 | 
. . 3
⊢ (((𝑥 ∈ 𝑆 ∧ 𝑦 ∈ 𝑆) ∧ (𝑧 ∈ 𝑆 ∧ 𝑤 ∈ 𝑆) ∧ (𝑣 ∈ 𝑆 ∧ 𝑢 ∈ 𝑆)) → (([〈𝑥, 𝑦〉] ∼ + [〈𝑧, 𝑤〉] ∼ ) + [〈𝑣, 𝑢〉] ∼ ) = [〈𝐽, 𝐾〉] ∼ ) | 
| 28 |   | ecovass.3 | 
. . . . . . 7
⊢ (((𝑧 ∈ 𝑆 ∧ 𝑤 ∈ 𝑆) ∧ (𝑣 ∈ 𝑆 ∧ 𝑢 ∈ 𝑆)) → ([〈𝑧, 𝑤〉] ∼ + [〈𝑣, 𝑢〉] ∼ ) = [〈𝑁, 𝑄〉] ∼ ) | 
| 29 | 28 | oveq2d 5938 | 
. . . . . 6
⊢ (((𝑧 ∈ 𝑆 ∧ 𝑤 ∈ 𝑆) ∧ (𝑣 ∈ 𝑆 ∧ 𝑢 ∈ 𝑆)) → ([〈𝑥, 𝑦〉] ∼ + ([〈𝑧, 𝑤〉] ∼ + [〈𝑣, 𝑢〉] ∼ )) = ([〈𝑥, 𝑦〉] ∼ + [〈𝑁, 𝑄〉] ∼ )) | 
| 30 | 29 | adantl 277 | 
. . . . 5
⊢ (((𝑥 ∈ 𝑆 ∧ 𝑦 ∈ 𝑆) ∧ ((𝑧 ∈ 𝑆 ∧ 𝑤 ∈ 𝑆) ∧ (𝑣 ∈ 𝑆 ∧ 𝑢 ∈ 𝑆))) → ([〈𝑥, 𝑦〉] ∼ + ([〈𝑧, 𝑤〉] ∼ + [〈𝑣, 𝑢〉] ∼ )) = ([〈𝑥, 𝑦〉] ∼ + [〈𝑁, 𝑄〉] ∼ )) | 
| 31 |   | ecovass.7 | 
. . . . . 6
⊢ (((𝑧 ∈ 𝑆 ∧ 𝑤 ∈ 𝑆) ∧ (𝑣 ∈ 𝑆 ∧ 𝑢 ∈ 𝑆)) → (𝑁 ∈ 𝑆 ∧ 𝑄 ∈ 𝑆)) | 
| 32 |   | ecovass.5 | 
. . . . . 6
⊢ (((𝑥 ∈ 𝑆 ∧ 𝑦 ∈ 𝑆) ∧ (𝑁 ∈ 𝑆 ∧ 𝑄 ∈ 𝑆)) → ([〈𝑥, 𝑦〉] ∼ + [〈𝑁, 𝑄〉] ∼ ) = [〈𝐿, 𝑀〉] ∼ ) | 
| 33 | 31, 32 | sylan2 286 | 
. . . . 5
⊢ (((𝑥 ∈ 𝑆 ∧ 𝑦 ∈ 𝑆) ∧ ((𝑧 ∈ 𝑆 ∧ 𝑤 ∈ 𝑆) ∧ (𝑣 ∈ 𝑆 ∧ 𝑢 ∈ 𝑆))) → ([〈𝑥, 𝑦〉] ∼ + [〈𝑁, 𝑄〉] ∼ ) = [〈𝐿, 𝑀〉] ∼ ) | 
| 34 | 30, 33 | eqtrd 2229 | 
. . . 4
⊢ (((𝑥 ∈ 𝑆 ∧ 𝑦 ∈ 𝑆) ∧ ((𝑧 ∈ 𝑆 ∧ 𝑤 ∈ 𝑆) ∧ (𝑣 ∈ 𝑆 ∧ 𝑢 ∈ 𝑆))) → ([〈𝑥, 𝑦〉] ∼ + ([〈𝑧, 𝑤〉] ∼ + [〈𝑣, 𝑢〉] ∼ )) = [〈𝐿, 𝑀〉] ∼ ) | 
| 35 | 34 | 3impb 1201 | 
. . 3
⊢ (((𝑥 ∈ 𝑆 ∧ 𝑦 ∈ 𝑆) ∧ (𝑧 ∈ 𝑆 ∧ 𝑤 ∈ 𝑆) ∧ (𝑣 ∈ 𝑆 ∧ 𝑢 ∈ 𝑆)) → ([〈𝑥, 𝑦〉] ∼ + ([〈𝑧, 𝑤〉] ∼ + [〈𝑣, 𝑢〉] ∼ )) = [〈𝐿, 𝑀〉] ∼ ) | 
| 36 | 19, 27, 35 | 3eqtr4a 2255 | 
. 2
⊢ (((𝑥 ∈ 𝑆 ∧ 𝑦 ∈ 𝑆) ∧ (𝑧 ∈ 𝑆 ∧ 𝑤 ∈ 𝑆) ∧ (𝑣 ∈ 𝑆 ∧ 𝑢 ∈ 𝑆)) → (([〈𝑥, 𝑦〉] ∼ + [〈𝑧, 𝑤〉] ∼ ) + [〈𝑣, 𝑢〉] ∼ ) = ([〈𝑥, 𝑦〉] ∼ + ([〈𝑧, 𝑤〉] ∼ + [〈𝑣, 𝑢〉] ∼
))) | 
| 37 | 1, 5, 10, 14, 36 | 3ecoptocl 6683 | 
1
⊢ ((𝐴 ∈ 𝐷 ∧ 𝐵 ∈ 𝐷 ∧ 𝐶 ∈ 𝐷) → ((𝐴 + 𝐵) + 𝐶) = (𝐴 + (𝐵 + 𝐶))) |