Proof of Theorem grpinvid1
| Step | Hyp | Ref | Expression | 
|---|
| 1 |  | oveq2 7440 | . . . 4
⊢ ((𝑁‘𝑋) = 𝑌 → (𝑋 + (𝑁‘𝑋)) = (𝑋 + 𝑌)) | 
| 2 | 1 | adantl 481 | . . 3
⊢ (((𝐺 ∈ Grp ∧ 𝑋 ∈ 𝐵 ∧ 𝑌 ∈ 𝐵) ∧ (𝑁‘𝑋) = 𝑌) → (𝑋 + (𝑁‘𝑋)) = (𝑋 + 𝑌)) | 
| 3 |  | grpinv.b | . . . . . 6
⊢ 𝐵 = (Base‘𝐺) | 
| 4 |  | grpinv.p | . . . . . 6
⊢  + =
(+g‘𝐺) | 
| 5 |  | grpinv.u | . . . . . 6
⊢  0 =
(0g‘𝐺) | 
| 6 |  | grpinv.n | . . . . . 6
⊢ 𝑁 = (invg‘𝐺) | 
| 7 | 3, 4, 5, 6 | grprinv 19009 | . . . . 5
⊢ ((𝐺 ∈ Grp ∧ 𝑋 ∈ 𝐵) → (𝑋 + (𝑁‘𝑋)) = 0 ) | 
| 8 | 7 | 3adant3 1132 | . . . 4
⊢ ((𝐺 ∈ Grp ∧ 𝑋 ∈ 𝐵 ∧ 𝑌 ∈ 𝐵) → (𝑋 + (𝑁‘𝑋)) = 0 ) | 
| 9 | 8 | adantr 480 | . . 3
⊢ (((𝐺 ∈ Grp ∧ 𝑋 ∈ 𝐵 ∧ 𝑌 ∈ 𝐵) ∧ (𝑁‘𝑋) = 𝑌) → (𝑋 + (𝑁‘𝑋)) = 0 ) | 
| 10 | 2, 9 | eqtr3d 2778 | . 2
⊢ (((𝐺 ∈ Grp ∧ 𝑋 ∈ 𝐵 ∧ 𝑌 ∈ 𝐵) ∧ (𝑁‘𝑋) = 𝑌) → (𝑋 + 𝑌) = 0 ) | 
| 11 |  | oveq2 7440 | . . . 4
⊢ ((𝑋 + 𝑌) = 0 → ((𝑁‘𝑋) + (𝑋 + 𝑌)) = ((𝑁‘𝑋) + 0 )) | 
| 12 | 11 | adantl 481 | . . 3
⊢ (((𝐺 ∈ Grp ∧ 𝑋 ∈ 𝐵 ∧ 𝑌 ∈ 𝐵) ∧ (𝑋 + 𝑌) = 0 ) → ((𝑁‘𝑋) + (𝑋 + 𝑌)) = ((𝑁‘𝑋) + 0 )) | 
| 13 | 3, 4, 5, 6 | grplinv 19008 | . . . . . . . 8
⊢ ((𝐺 ∈ Grp ∧ 𝑋 ∈ 𝐵) → ((𝑁‘𝑋) + 𝑋) = 0 ) | 
| 14 | 13 | oveq1d 7447 | . . . . . . 7
⊢ ((𝐺 ∈ Grp ∧ 𝑋 ∈ 𝐵) → (((𝑁‘𝑋) + 𝑋) + 𝑌) = ( 0 + 𝑌)) | 
| 15 | 14 | 3adant3 1132 | . . . . . 6
⊢ ((𝐺 ∈ Grp ∧ 𝑋 ∈ 𝐵 ∧ 𝑌 ∈ 𝐵) → (((𝑁‘𝑋) + 𝑋) + 𝑌) = ( 0 + 𝑌)) | 
| 16 | 3, 6 | grpinvcl 19006 | . . . . . . . . . 10
⊢ ((𝐺 ∈ Grp ∧ 𝑋 ∈ 𝐵) → (𝑁‘𝑋) ∈ 𝐵) | 
| 17 | 16 | adantrr 717 | . . . . . . . . 9
⊢ ((𝐺 ∈ Grp ∧ (𝑋 ∈ 𝐵 ∧ 𝑌 ∈ 𝐵)) → (𝑁‘𝑋) ∈ 𝐵) | 
| 18 |  | simprl 770 | . . . . . . . . 9
⊢ ((𝐺 ∈ Grp ∧ (𝑋 ∈ 𝐵 ∧ 𝑌 ∈ 𝐵)) → 𝑋 ∈ 𝐵) | 
| 19 |  | simprr 772 | . . . . . . . . 9
⊢ ((𝐺 ∈ Grp ∧ (𝑋 ∈ 𝐵 ∧ 𝑌 ∈ 𝐵)) → 𝑌 ∈ 𝐵) | 
| 20 | 17, 18, 19 | 3jca 1128 | . . . . . . . 8
⊢ ((𝐺 ∈ Grp ∧ (𝑋 ∈ 𝐵 ∧ 𝑌 ∈ 𝐵)) → ((𝑁‘𝑋) ∈ 𝐵 ∧ 𝑋 ∈ 𝐵 ∧ 𝑌 ∈ 𝐵)) | 
| 21 | 3, 4 | grpass 18961 | . . . . . . . 8
⊢ ((𝐺 ∈ Grp ∧ ((𝑁‘𝑋) ∈ 𝐵 ∧ 𝑋 ∈ 𝐵 ∧ 𝑌 ∈ 𝐵)) → (((𝑁‘𝑋) + 𝑋) + 𝑌) = ((𝑁‘𝑋) + (𝑋 + 𝑌))) | 
| 22 | 20, 21 | syldan 591 | . . . . . . 7
⊢ ((𝐺 ∈ Grp ∧ (𝑋 ∈ 𝐵 ∧ 𝑌 ∈ 𝐵)) → (((𝑁‘𝑋) + 𝑋) + 𝑌) = ((𝑁‘𝑋) + (𝑋 + 𝑌))) | 
| 23 | 22 | 3impb 1114 | . . . . . 6
⊢ ((𝐺 ∈ Grp ∧ 𝑋 ∈ 𝐵 ∧ 𝑌 ∈ 𝐵) → (((𝑁‘𝑋) + 𝑋) + 𝑌) = ((𝑁‘𝑋) + (𝑋 + 𝑌))) | 
| 24 | 15, 23 | eqtr3d 2778 | . . . . 5
⊢ ((𝐺 ∈ Grp ∧ 𝑋 ∈ 𝐵 ∧ 𝑌 ∈ 𝐵) → ( 0 + 𝑌) = ((𝑁‘𝑋) + (𝑋 + 𝑌))) | 
| 25 | 3, 4, 5 | grplid 18986 | . . . . . 6
⊢ ((𝐺 ∈ Grp ∧ 𝑌 ∈ 𝐵) → ( 0 + 𝑌) = 𝑌) | 
| 26 | 25 | 3adant2 1131 | . . . . 5
⊢ ((𝐺 ∈ Grp ∧ 𝑋 ∈ 𝐵 ∧ 𝑌 ∈ 𝐵) → ( 0 + 𝑌) = 𝑌) | 
| 27 | 24, 26 | eqtr3d 2778 | . . . 4
⊢ ((𝐺 ∈ Grp ∧ 𝑋 ∈ 𝐵 ∧ 𝑌 ∈ 𝐵) → ((𝑁‘𝑋) + (𝑋 + 𝑌)) = 𝑌) | 
| 28 | 27 | adantr 480 | . . 3
⊢ (((𝐺 ∈ Grp ∧ 𝑋 ∈ 𝐵 ∧ 𝑌 ∈ 𝐵) ∧ (𝑋 + 𝑌) = 0 ) → ((𝑁‘𝑋) + (𝑋 + 𝑌)) = 𝑌) | 
| 29 | 3, 4, 5 | grprid 18987 | . . . . . 6
⊢ ((𝐺 ∈ Grp ∧ (𝑁‘𝑋) ∈ 𝐵) → ((𝑁‘𝑋) + 0 ) = (𝑁‘𝑋)) | 
| 30 | 16, 29 | syldan 591 | . . . . 5
⊢ ((𝐺 ∈ Grp ∧ 𝑋 ∈ 𝐵) → ((𝑁‘𝑋) + 0 ) = (𝑁‘𝑋)) | 
| 31 | 30 | 3adant3 1132 | . . . 4
⊢ ((𝐺 ∈ Grp ∧ 𝑋 ∈ 𝐵 ∧ 𝑌 ∈ 𝐵) → ((𝑁‘𝑋) + 0 ) = (𝑁‘𝑋)) | 
| 32 | 31 | adantr 480 | . . 3
⊢ (((𝐺 ∈ Grp ∧ 𝑋 ∈ 𝐵 ∧ 𝑌 ∈ 𝐵) ∧ (𝑋 + 𝑌) = 0 ) → ((𝑁‘𝑋) + 0 ) = (𝑁‘𝑋)) | 
| 33 | 12, 28, 32 | 3eqtr3rd 2785 | . 2
⊢ (((𝐺 ∈ Grp ∧ 𝑋 ∈ 𝐵 ∧ 𝑌 ∈ 𝐵) ∧ (𝑋 + 𝑌) = 0 ) → (𝑁‘𝑋) = 𝑌) | 
| 34 | 10, 33 | impbida 800 | 1
⊢ ((𝐺 ∈ Grp ∧ 𝑋 ∈ 𝐵 ∧ 𝑌 ∈ 𝐵) → ((𝑁‘𝑋) = 𝑌 ↔ (𝑋 + 𝑌) = 0 )) |