Proof of Theorem symggrplem
| Step | Hyp | Ref | Expression | 
|---|
| 1 |  | coass 6285 | . 2
⊢ ((𝑋 ∘ 𝑌) ∘ 𝑍) = (𝑋 ∘ (𝑌 ∘ 𝑍)) | 
| 2 |  | oveq1 7438 | . . . . . 6
⊢ (𝑥 = 𝑋 → (𝑥 + 𝑦) = (𝑋 + 𝑦)) | 
| 3 | 2 | eleq1d 2826 | . . . . 5
⊢ (𝑥 = 𝑋 → ((𝑥 + 𝑦) ∈ 𝐵 ↔ (𝑋 + 𝑦) ∈ 𝐵)) | 
| 4 |  | oveq2 7439 | . . . . . 6
⊢ (𝑦 = 𝑌 → (𝑋 + 𝑦) = (𝑋 + 𝑌)) | 
| 5 | 4 | eleq1d 2826 | . . . . 5
⊢ (𝑦 = 𝑌 → ((𝑋 + 𝑦) ∈ 𝐵 ↔ (𝑋 + 𝑌) ∈ 𝐵)) | 
| 6 |  | symggrplem.c | . . . . 5
⊢ ((𝑥 ∈ 𝐵 ∧ 𝑦 ∈ 𝐵) → (𝑥 + 𝑦) ∈ 𝐵) | 
| 7 | 3, 5, 6 | vtocl2ga 3578 | . . . 4
⊢ ((𝑋 ∈ 𝐵 ∧ 𝑌 ∈ 𝐵) → (𝑋 + 𝑌) ∈ 𝐵) | 
| 8 |  | oveq1 7438 | . . . . . 6
⊢ (𝑥 = (𝑋 + 𝑌) → (𝑥 + 𝑦) = ((𝑋 + 𝑌) + 𝑦)) | 
| 9 |  | coeq1 5868 | . . . . . 6
⊢ (𝑥 = (𝑋 + 𝑌) → (𝑥 ∘ 𝑦) = ((𝑋 + 𝑌) ∘ 𝑦)) | 
| 10 | 8, 9 | eqeq12d 2753 | . . . . 5
⊢ (𝑥 = (𝑋 + 𝑌) → ((𝑥 + 𝑦) = (𝑥 ∘ 𝑦) ↔ ((𝑋 + 𝑌) + 𝑦) = ((𝑋 + 𝑌) ∘ 𝑦))) | 
| 11 |  | oveq2 7439 | . . . . . 6
⊢ (𝑦 = 𝑍 → ((𝑋 + 𝑌) + 𝑦) = ((𝑋 + 𝑌) + 𝑍)) | 
| 12 |  | coeq2 5869 | . . . . . 6
⊢ (𝑦 = 𝑍 → ((𝑋 + 𝑌) ∘ 𝑦) = ((𝑋 + 𝑌) ∘ 𝑍)) | 
| 13 | 11, 12 | eqeq12d 2753 | . . . . 5
⊢ (𝑦 = 𝑍 → (((𝑋 + 𝑌) + 𝑦) = ((𝑋 + 𝑌) ∘ 𝑦) ↔ ((𝑋 + 𝑌) + 𝑍) = ((𝑋 + 𝑌) ∘ 𝑍))) | 
| 14 |  | symggrplem.p | . . . . 5
⊢ ((𝑥 ∈ 𝐵 ∧ 𝑦 ∈ 𝐵) → (𝑥 + 𝑦) = (𝑥 ∘ 𝑦)) | 
| 15 | 10, 13, 14 | vtocl2ga 3578 | . . . 4
⊢ (((𝑋 + 𝑌) ∈ 𝐵 ∧ 𝑍 ∈ 𝐵) → ((𝑋 + 𝑌) + 𝑍) = ((𝑋 + 𝑌) ∘ 𝑍)) | 
| 16 | 7, 15 | stoic3 1776 | . . 3
⊢ ((𝑋 ∈ 𝐵 ∧ 𝑌 ∈ 𝐵 ∧ 𝑍 ∈ 𝐵) → ((𝑋 + 𝑌) + 𝑍) = ((𝑋 + 𝑌) ∘ 𝑍)) | 
| 17 |  | coeq1 5868 | . . . . . . 7
⊢ (𝑥 = 𝑋 → (𝑥 ∘ 𝑦) = (𝑋 ∘ 𝑦)) | 
| 18 | 2, 17 | eqeq12d 2753 | . . . . . 6
⊢ (𝑥 = 𝑋 → ((𝑥 + 𝑦) = (𝑥 ∘ 𝑦) ↔ (𝑋 + 𝑦) = (𝑋 ∘ 𝑦))) | 
| 19 |  | coeq2 5869 | . . . . . . 7
⊢ (𝑦 = 𝑌 → (𝑋 ∘ 𝑦) = (𝑋 ∘ 𝑌)) | 
| 20 | 4, 19 | eqeq12d 2753 | . . . . . 6
⊢ (𝑦 = 𝑌 → ((𝑋 + 𝑦) = (𝑋 ∘ 𝑦) ↔ (𝑋 + 𝑌) = (𝑋 ∘ 𝑌))) | 
| 21 | 18, 20, 14 | vtocl2ga 3578 | . . . . 5
⊢ ((𝑋 ∈ 𝐵 ∧ 𝑌 ∈ 𝐵) → (𝑋 + 𝑌) = (𝑋 ∘ 𝑌)) | 
| 22 | 21 | 3adant3 1133 | . . . 4
⊢ ((𝑋 ∈ 𝐵 ∧ 𝑌 ∈ 𝐵 ∧ 𝑍 ∈ 𝐵) → (𝑋 + 𝑌) = (𝑋 ∘ 𝑌)) | 
| 23 | 22 | coeq1d 5872 | . . 3
⊢ ((𝑋 ∈ 𝐵 ∧ 𝑌 ∈ 𝐵 ∧ 𝑍 ∈ 𝐵) → ((𝑋 + 𝑌) ∘ 𝑍) = ((𝑋 ∘ 𝑌) ∘ 𝑍)) | 
| 24 | 16, 23 | eqtrd 2777 | . 2
⊢ ((𝑋 ∈ 𝐵 ∧ 𝑌 ∈ 𝐵 ∧ 𝑍 ∈ 𝐵) → ((𝑋 + 𝑌) + 𝑍) = ((𝑋 ∘ 𝑌) ∘ 𝑍)) | 
| 25 |  | simp1 1137 | . . . 4
⊢ ((𝑋 ∈ 𝐵 ∧ 𝑌 ∈ 𝐵 ∧ 𝑍 ∈ 𝐵) → 𝑋 ∈ 𝐵) | 
| 26 |  | oveq1 7438 | . . . . . . 7
⊢ (𝑥 = 𝑌 → (𝑥 + 𝑦) = (𝑌 + 𝑦)) | 
| 27 | 26 | eleq1d 2826 | . . . . . 6
⊢ (𝑥 = 𝑌 → ((𝑥 + 𝑦) ∈ 𝐵 ↔ (𝑌 + 𝑦) ∈ 𝐵)) | 
| 28 |  | oveq2 7439 | . . . . . . 7
⊢ (𝑦 = 𝑍 → (𝑌 + 𝑦) = (𝑌 + 𝑍)) | 
| 29 | 28 | eleq1d 2826 | . . . . . 6
⊢ (𝑦 = 𝑍 → ((𝑌 + 𝑦) ∈ 𝐵 ↔ (𝑌 + 𝑍) ∈ 𝐵)) | 
| 30 | 27, 29, 6 | vtocl2ga 3578 | . . . . 5
⊢ ((𝑌 ∈ 𝐵 ∧ 𝑍 ∈ 𝐵) → (𝑌 + 𝑍) ∈ 𝐵) | 
| 31 | 30 | 3adant1 1131 | . . . 4
⊢ ((𝑋 ∈ 𝐵 ∧ 𝑌 ∈ 𝐵 ∧ 𝑍 ∈ 𝐵) → (𝑌 + 𝑍) ∈ 𝐵) | 
| 32 |  | oveq2 7439 | . . . . . 6
⊢ (𝑦 = (𝑌 + 𝑍) → (𝑋 + 𝑦) = (𝑋 + (𝑌 + 𝑍))) | 
| 33 |  | coeq2 5869 | . . . . . 6
⊢ (𝑦 = (𝑌 + 𝑍) → (𝑋 ∘ 𝑦) = (𝑋 ∘ (𝑌 + 𝑍))) | 
| 34 | 32, 33 | eqeq12d 2753 | . . . . 5
⊢ (𝑦 = (𝑌 + 𝑍) → ((𝑋 + 𝑦) = (𝑋 ∘ 𝑦) ↔ (𝑋 + (𝑌 + 𝑍)) = (𝑋 ∘ (𝑌 + 𝑍)))) | 
| 35 | 18, 34, 14 | vtocl2ga 3578 | . . . 4
⊢ ((𝑋 ∈ 𝐵 ∧ (𝑌 + 𝑍) ∈ 𝐵) → (𝑋 + (𝑌 + 𝑍)) = (𝑋 ∘ (𝑌 + 𝑍))) | 
| 36 | 25, 31, 35 | syl2anc 584 | . . 3
⊢ ((𝑋 ∈ 𝐵 ∧ 𝑌 ∈ 𝐵 ∧ 𝑍 ∈ 𝐵) → (𝑋 + (𝑌 + 𝑍)) = (𝑋 ∘ (𝑌 + 𝑍))) | 
| 37 |  | coeq1 5868 | . . . . . . 7
⊢ (𝑥 = 𝑌 → (𝑥 ∘ 𝑦) = (𝑌 ∘ 𝑦)) | 
| 38 | 26, 37 | eqeq12d 2753 | . . . . . 6
⊢ (𝑥 = 𝑌 → ((𝑥 + 𝑦) = (𝑥 ∘ 𝑦) ↔ (𝑌 + 𝑦) = (𝑌 ∘ 𝑦))) | 
| 39 |  | coeq2 5869 | . . . . . . 7
⊢ (𝑦 = 𝑍 → (𝑌 ∘ 𝑦) = (𝑌 ∘ 𝑍)) | 
| 40 | 28, 39 | eqeq12d 2753 | . . . . . 6
⊢ (𝑦 = 𝑍 → ((𝑌 + 𝑦) = (𝑌 ∘ 𝑦) ↔ (𝑌 + 𝑍) = (𝑌 ∘ 𝑍))) | 
| 41 | 38, 40, 14 | vtocl2ga 3578 | . . . . 5
⊢ ((𝑌 ∈ 𝐵 ∧ 𝑍 ∈ 𝐵) → (𝑌 + 𝑍) = (𝑌 ∘ 𝑍)) | 
| 42 | 41 | 3adant1 1131 | . . . 4
⊢ ((𝑋 ∈ 𝐵 ∧ 𝑌 ∈ 𝐵 ∧ 𝑍 ∈ 𝐵) → (𝑌 + 𝑍) = (𝑌 ∘ 𝑍)) | 
| 43 | 42 | coeq2d 5873 | . . 3
⊢ ((𝑋 ∈ 𝐵 ∧ 𝑌 ∈ 𝐵 ∧ 𝑍 ∈ 𝐵) → (𝑋 ∘ (𝑌 + 𝑍)) = (𝑋 ∘ (𝑌 ∘ 𝑍))) | 
| 44 | 36, 43 | eqtrd 2777 | . 2
⊢ ((𝑋 ∈ 𝐵 ∧ 𝑌 ∈ 𝐵 ∧ 𝑍 ∈ 𝐵) → (𝑋 + (𝑌 + 𝑍)) = (𝑋 ∘ (𝑌 ∘ 𝑍))) | 
| 45 | 1, 24, 44 | 3eqtr4a 2803 | 1
⊢ ((𝑋 ∈ 𝐵 ∧ 𝑌 ∈ 𝐵 ∧ 𝑍 ∈ 𝐵) → ((𝑋 + 𝑌) + 𝑍) = (𝑋 + (𝑌 + 𝑍))) |