| Step | Hyp | Ref
 | Expression | 
| 1 |   | eqid 2196 | 
. 2
⊢
(Base‘(oppr‘𝑅)) =
(Base‘(oppr‘𝑅)) | 
| 2 |   | eqid 2196 | 
. 2
⊢
(1r‘(oppr‘𝑅)) =
(1r‘(oppr‘𝑅)) | 
| 3 |   | eqid 2196 | 
. 2
⊢
(1r‘(oppr‘𝑆)) =
(1r‘(oppr‘𝑆)) | 
| 4 |   | eqid 2196 | 
. 2
⊢
(.r‘(oppr‘𝑅)) =
(.r‘(oppr‘𝑅)) | 
| 5 |   | eqid 2196 | 
. 2
⊢
(.r‘(oppr‘𝑆)) =
(.r‘(oppr‘𝑆)) | 
| 6 |   | rhmrcl1 13711 | 
. . 3
⊢ (𝐹 ∈ (𝑅 RingHom 𝑆) → 𝑅 ∈ Ring) | 
| 7 |   | eqid 2196 | 
. . . . 5
⊢
(oppr‘𝑅) = (oppr‘𝑅) | 
| 8 | 7 | opprringbg 13636 | 
. . . 4
⊢ (𝑅 ∈ Ring → (𝑅 ∈ Ring ↔
(oppr‘𝑅) ∈ Ring)) | 
| 9 | 6, 8 | syl 14 | 
. . 3
⊢ (𝐹 ∈ (𝑅 RingHom 𝑆) → (𝑅 ∈ Ring ↔
(oppr‘𝑅) ∈ Ring)) | 
| 10 | 6, 9 | mpbid 147 | 
. 2
⊢ (𝐹 ∈ (𝑅 RingHom 𝑆) → (oppr‘𝑅) ∈ Ring) | 
| 11 |   | rhmrcl2 13712 | 
. . 3
⊢ (𝐹 ∈ (𝑅 RingHom 𝑆) → 𝑆 ∈ Ring) | 
| 12 |   | eqid 2196 | 
. . . . 5
⊢
(oppr‘𝑆) = (oppr‘𝑆) | 
| 13 | 12 | opprringbg 13636 | 
. . . 4
⊢ (𝑆 ∈ Ring → (𝑆 ∈ Ring ↔
(oppr‘𝑆) ∈ Ring)) | 
| 14 | 11, 13 | syl 14 | 
. . 3
⊢ (𝐹 ∈ (𝑅 RingHom 𝑆) → (𝑆 ∈ Ring ↔
(oppr‘𝑆) ∈ Ring)) | 
| 15 | 11, 14 | mpbid 147 | 
. 2
⊢ (𝐹 ∈ (𝑅 RingHom 𝑆) → (oppr‘𝑆) ∈ Ring) | 
| 16 |   | eqid 2196 | 
. . . 4
⊢
(1r‘𝑅) = (1r‘𝑅) | 
| 17 |   | eqid 2196 | 
. . . 4
⊢
(1r‘𝑆) = (1r‘𝑆) | 
| 18 | 16, 17 | rhm1 13723 | 
. . 3
⊢ (𝐹 ∈ (𝑅 RingHom 𝑆) → (𝐹‘(1r‘𝑅)) = (1r‘𝑆)) | 
| 19 | 7, 16 | oppr1g 13638 | 
. . . . . 6
⊢ (𝑅 ∈ Ring →
(1r‘𝑅) =
(1r‘(oppr‘𝑅))) | 
| 20 | 6, 19 | syl 14 | 
. . . . 5
⊢ (𝐹 ∈ (𝑅 RingHom 𝑆) → (1r‘𝑅) =
(1r‘(oppr‘𝑅))) | 
| 21 | 20 | eqcomd 2202 | 
. . . 4
⊢ (𝐹 ∈ (𝑅 RingHom 𝑆) →
(1r‘(oppr‘𝑅)) = (1r‘𝑅)) | 
| 22 | 21 | fveq2d 5562 | 
. . 3
⊢ (𝐹 ∈ (𝑅 RingHom 𝑆) → (𝐹‘(1r‘(oppr‘𝑅))) = (𝐹‘(1r‘𝑅))) | 
| 23 | 12, 17 | oppr1g 13638 | 
. . . . 5
⊢ (𝑆 ∈ Ring →
(1r‘𝑆) =
(1r‘(oppr‘𝑆))) | 
| 24 | 11, 23 | syl 14 | 
. . . 4
⊢ (𝐹 ∈ (𝑅 RingHom 𝑆) → (1r‘𝑆) =
(1r‘(oppr‘𝑆))) | 
| 25 | 24 | eqcomd 2202 | 
. . 3
⊢ (𝐹 ∈ (𝑅 RingHom 𝑆) →
(1r‘(oppr‘𝑆)) = (1r‘𝑆)) | 
| 26 | 18, 22, 25 | 3eqtr4d 2239 | 
. 2
⊢ (𝐹 ∈ (𝑅 RingHom 𝑆) → (𝐹‘(1r‘(oppr‘𝑅))) =
(1r‘(oppr‘𝑆))) | 
| 27 |   | simpl 109 | 
. . . 4
⊢ ((𝐹 ∈ (𝑅 RingHom 𝑆) ∧ (𝑥 ∈
(Base‘(oppr‘𝑅)) ∧ 𝑦 ∈
(Base‘(oppr‘𝑅)))) → 𝐹 ∈ (𝑅 RingHom 𝑆)) | 
| 28 |   | simprr 531 | 
. . . . 5
⊢ ((𝐹 ∈ (𝑅 RingHom 𝑆) ∧ (𝑥 ∈
(Base‘(oppr‘𝑅)) ∧ 𝑦 ∈
(Base‘(oppr‘𝑅)))) → 𝑦 ∈
(Base‘(oppr‘𝑅))) | 
| 29 |   | eqid 2196 | 
. . . . . . . 8
⊢
(Base‘𝑅) =
(Base‘𝑅) | 
| 30 | 7, 29 | opprbasg 13631 | 
. . . . . . 7
⊢ (𝑅 ∈ Ring →
(Base‘𝑅) =
(Base‘(oppr‘𝑅))) | 
| 31 | 6, 30 | syl 14 | 
. . . . . 6
⊢ (𝐹 ∈ (𝑅 RingHom 𝑆) → (Base‘𝑅) =
(Base‘(oppr‘𝑅))) | 
| 32 | 27, 31 | syl 14 | 
. . . . 5
⊢ ((𝐹 ∈ (𝑅 RingHom 𝑆) ∧ (𝑥 ∈
(Base‘(oppr‘𝑅)) ∧ 𝑦 ∈
(Base‘(oppr‘𝑅)))) → (Base‘𝑅) =
(Base‘(oppr‘𝑅))) | 
| 33 | 28, 32 | eleqtrrd 2276 | 
. . . 4
⊢ ((𝐹 ∈ (𝑅 RingHom 𝑆) ∧ (𝑥 ∈
(Base‘(oppr‘𝑅)) ∧ 𝑦 ∈
(Base‘(oppr‘𝑅)))) → 𝑦 ∈ (Base‘𝑅)) | 
| 34 |   | simprl 529 | 
. . . . 5
⊢ ((𝐹 ∈ (𝑅 RingHom 𝑆) ∧ (𝑥 ∈
(Base‘(oppr‘𝑅)) ∧ 𝑦 ∈
(Base‘(oppr‘𝑅)))) → 𝑥 ∈
(Base‘(oppr‘𝑅))) | 
| 35 | 34, 32 | eleqtrrd 2276 | 
. . . 4
⊢ ((𝐹 ∈ (𝑅 RingHom 𝑆) ∧ (𝑥 ∈
(Base‘(oppr‘𝑅)) ∧ 𝑦 ∈
(Base‘(oppr‘𝑅)))) → 𝑥 ∈ (Base‘𝑅)) | 
| 36 |   | eqid 2196 | 
. . . . 5
⊢
(.r‘𝑅) = (.r‘𝑅) | 
| 37 |   | eqid 2196 | 
. . . . 5
⊢
(.r‘𝑆) = (.r‘𝑆) | 
| 38 | 29, 36, 37 | rhmmul 13720 | 
. . . 4
⊢ ((𝐹 ∈ (𝑅 RingHom 𝑆) ∧ 𝑦 ∈ (Base‘𝑅) ∧ 𝑥 ∈ (Base‘𝑅)) → (𝐹‘(𝑦(.r‘𝑅)𝑥)) = ((𝐹‘𝑦)(.r‘𝑆)(𝐹‘𝑥))) | 
| 39 | 27, 33, 35, 38 | syl3anc 1249 | 
. . 3
⊢ ((𝐹 ∈ (𝑅 RingHom 𝑆) ∧ (𝑥 ∈
(Base‘(oppr‘𝑅)) ∧ 𝑦 ∈
(Base‘(oppr‘𝑅)))) → (𝐹‘(𝑦(.r‘𝑅)𝑥)) = ((𝐹‘𝑦)(.r‘𝑆)(𝐹‘𝑥))) | 
| 40 | 27, 6 | syl 14 | 
. . . . 5
⊢ ((𝐹 ∈ (𝑅 RingHom 𝑆) ∧ (𝑥 ∈
(Base‘(oppr‘𝑅)) ∧ 𝑦 ∈
(Base‘(oppr‘𝑅)))) → 𝑅 ∈ Ring) | 
| 41 | 29, 36, 7, 4 | opprmulg 13627 | 
. . . . 5
⊢ ((𝑅 ∈ Ring ∧ 𝑥 ∈
(Base‘(oppr‘𝑅)) ∧ 𝑦 ∈
(Base‘(oppr‘𝑅))) → (𝑥(.r‘(oppr‘𝑅))𝑦) = (𝑦(.r‘𝑅)𝑥)) | 
| 42 | 40, 34, 28, 41 | syl3anc 1249 | 
. . . 4
⊢ ((𝐹 ∈ (𝑅 RingHom 𝑆) ∧ (𝑥 ∈
(Base‘(oppr‘𝑅)) ∧ 𝑦 ∈
(Base‘(oppr‘𝑅)))) → (𝑥(.r‘(oppr‘𝑅))𝑦) = (𝑦(.r‘𝑅)𝑥)) | 
| 43 | 42 | fveq2d 5562 | 
. . 3
⊢ ((𝐹 ∈ (𝑅 RingHom 𝑆) ∧ (𝑥 ∈
(Base‘(oppr‘𝑅)) ∧ 𝑦 ∈
(Base‘(oppr‘𝑅)))) → (𝐹‘(𝑥(.r‘(oppr‘𝑅))𝑦)) = (𝐹‘(𝑦(.r‘𝑅)𝑥))) | 
| 44 | 27, 11 | syl 14 | 
. . . 4
⊢ ((𝐹 ∈ (𝑅 RingHom 𝑆) ∧ (𝑥 ∈
(Base‘(oppr‘𝑅)) ∧ 𝑦 ∈
(Base‘(oppr‘𝑅)))) → 𝑆 ∈ Ring) | 
| 45 |   | eqid 2196 | 
. . . . . . 7
⊢
(Base‘𝑆) =
(Base‘𝑆) | 
| 46 | 29, 45 | rhmf 13719 | 
. . . . . 6
⊢ (𝐹 ∈ (𝑅 RingHom 𝑆) → 𝐹:(Base‘𝑅)⟶(Base‘𝑆)) | 
| 47 | 27, 46 | syl 14 | 
. . . . 5
⊢ ((𝐹 ∈ (𝑅 RingHom 𝑆) ∧ (𝑥 ∈
(Base‘(oppr‘𝑅)) ∧ 𝑦 ∈
(Base‘(oppr‘𝑅)))) → 𝐹:(Base‘𝑅)⟶(Base‘𝑆)) | 
| 48 | 47, 35 | ffvelcdmd 5698 | 
. . . 4
⊢ ((𝐹 ∈ (𝑅 RingHom 𝑆) ∧ (𝑥 ∈
(Base‘(oppr‘𝑅)) ∧ 𝑦 ∈
(Base‘(oppr‘𝑅)))) → (𝐹‘𝑥) ∈ (Base‘𝑆)) | 
| 49 | 47, 33 | ffvelcdmd 5698 | 
. . . 4
⊢ ((𝐹 ∈ (𝑅 RingHom 𝑆) ∧ (𝑥 ∈
(Base‘(oppr‘𝑅)) ∧ 𝑦 ∈
(Base‘(oppr‘𝑅)))) → (𝐹‘𝑦) ∈ (Base‘𝑆)) | 
| 50 | 45, 37, 12, 5 | opprmulg 13627 | 
. . . 4
⊢ ((𝑆 ∈ Ring ∧ (𝐹‘𝑥) ∈ (Base‘𝑆) ∧ (𝐹‘𝑦) ∈ (Base‘𝑆)) → ((𝐹‘𝑥)(.r‘(oppr‘𝑆))(𝐹‘𝑦)) = ((𝐹‘𝑦)(.r‘𝑆)(𝐹‘𝑥))) | 
| 51 | 44, 48, 49, 50 | syl3anc 1249 | 
. . 3
⊢ ((𝐹 ∈ (𝑅 RingHom 𝑆) ∧ (𝑥 ∈
(Base‘(oppr‘𝑅)) ∧ 𝑦 ∈
(Base‘(oppr‘𝑅)))) → ((𝐹‘𝑥)(.r‘(oppr‘𝑆))(𝐹‘𝑦)) = ((𝐹‘𝑦)(.r‘𝑆)(𝐹‘𝑥))) | 
| 52 | 39, 43, 51 | 3eqtr4d 2239 | 
. 2
⊢ ((𝐹 ∈ (𝑅 RingHom 𝑆) ∧ (𝑥 ∈
(Base‘(oppr‘𝑅)) ∧ 𝑦 ∈
(Base‘(oppr‘𝑅)))) → (𝐹‘(𝑥(.r‘(oppr‘𝑅))𝑦)) = ((𝐹‘𝑥)(.r‘(oppr‘𝑆))(𝐹‘𝑦))) | 
| 53 | 10 | ringgrpd 13561 | 
. . . . 5
⊢ (𝐹 ∈ (𝑅 RingHom 𝑆) → (oppr‘𝑅) ∈ Grp) | 
| 54 | 15 | ringgrpd 13561 | 
. . . . 5
⊢ (𝐹 ∈ (𝑅 RingHom 𝑆) → (oppr‘𝑆) ∈ Grp) | 
| 55 |   | rhmghm 13718 | 
. . . . . . . . . 10
⊢ (𝐹 ∈ (𝑅 RingHom 𝑆) → 𝐹 ∈ (𝑅 GrpHom 𝑆)) | 
| 56 | 55 | ad2antrr 488 | 
. . . . . . . . 9
⊢ (((𝐹 ∈ (𝑅 RingHom 𝑆) ∧ 𝑥 ∈ (Base‘𝑅)) ∧ 𝑦 ∈ (Base‘𝑅)) → 𝐹 ∈ (𝑅 GrpHom 𝑆)) | 
| 57 |   | simplr 528 | 
. . . . . . . . 9
⊢ (((𝐹 ∈ (𝑅 RingHom 𝑆) ∧ 𝑥 ∈ (Base‘𝑅)) ∧ 𝑦 ∈ (Base‘𝑅)) → 𝑥 ∈ (Base‘𝑅)) | 
| 58 |   | simpr 110 | 
. . . . . . . . 9
⊢ (((𝐹 ∈ (𝑅 RingHom 𝑆) ∧ 𝑥 ∈ (Base‘𝑅)) ∧ 𝑦 ∈ (Base‘𝑅)) → 𝑦 ∈ (Base‘𝑅)) | 
| 59 |   | eqid 2196 | 
. . . . . . . . . 10
⊢
(+g‘𝑅) = (+g‘𝑅) | 
| 60 |   | eqid 2196 | 
. . . . . . . . . 10
⊢
(+g‘𝑆) = (+g‘𝑆) | 
| 61 | 29, 59, 60 | ghmlin 13378 | 
. . . . . . . . 9
⊢ ((𝐹 ∈ (𝑅 GrpHom 𝑆) ∧ 𝑥 ∈ (Base‘𝑅) ∧ 𝑦 ∈ (Base‘𝑅)) → (𝐹‘(𝑥(+g‘𝑅)𝑦)) = ((𝐹‘𝑥)(+g‘𝑆)(𝐹‘𝑦))) | 
| 62 | 56, 57, 58, 61 | syl3anc 1249 | 
. . . . . . . 8
⊢ (((𝐹 ∈ (𝑅 RingHom 𝑆) ∧ 𝑥 ∈ (Base‘𝑅)) ∧ 𝑦 ∈ (Base‘𝑅)) → (𝐹‘(𝑥(+g‘𝑅)𝑦)) = ((𝐹‘𝑥)(+g‘𝑆)(𝐹‘𝑦))) | 
| 63 | 62 | ralrimiva 2570 | 
. . . . . . 7
⊢ ((𝐹 ∈ (𝑅 RingHom 𝑆) ∧ 𝑥 ∈ (Base‘𝑅)) → ∀𝑦 ∈ (Base‘𝑅)(𝐹‘(𝑥(+g‘𝑅)𝑦)) = ((𝐹‘𝑥)(+g‘𝑆)(𝐹‘𝑦))) | 
| 64 | 63 | ralrimiva 2570 | 
. . . . . 6
⊢ (𝐹 ∈ (𝑅 RingHom 𝑆) → ∀𝑥 ∈ (Base‘𝑅)∀𝑦 ∈ (Base‘𝑅)(𝐹‘(𝑥(+g‘𝑅)𝑦)) = ((𝐹‘𝑥)(+g‘𝑆)(𝐹‘𝑦))) | 
| 65 | 46, 64 | jca 306 | 
. . . . 5
⊢ (𝐹 ∈ (𝑅 RingHom 𝑆) → (𝐹:(Base‘𝑅)⟶(Base‘𝑆) ∧ ∀𝑥 ∈ (Base‘𝑅)∀𝑦 ∈ (Base‘𝑅)(𝐹‘(𝑥(+g‘𝑅)𝑦)) = ((𝐹‘𝑥)(+g‘𝑆)(𝐹‘𝑦)))) | 
| 66 | 53, 54, 65 | jca31 309 | 
. . . 4
⊢ (𝐹 ∈ (𝑅 RingHom 𝑆) →
(((oppr‘𝑅) ∈ Grp ∧
(oppr‘𝑆) ∈ Grp) ∧ (𝐹:(Base‘𝑅)⟶(Base‘𝑆) ∧ ∀𝑥 ∈ (Base‘𝑅)∀𝑦 ∈ (Base‘𝑅)(𝐹‘(𝑥(+g‘𝑅)𝑦)) = ((𝐹‘𝑥)(+g‘𝑆)(𝐹‘𝑦))))) | 
| 67 | 12, 45 | opprbasg 13631 | 
. . . . . . . 8
⊢ (𝑆 ∈ Ring →
(Base‘𝑆) =
(Base‘(oppr‘𝑆))) | 
| 68 | 11, 67 | syl 14 | 
. . . . . . 7
⊢ (𝐹 ∈ (𝑅 RingHom 𝑆) → (Base‘𝑆) =
(Base‘(oppr‘𝑆))) | 
| 69 | 31, 68 | feq23d 5403 | 
. . . . . 6
⊢ (𝐹 ∈ (𝑅 RingHom 𝑆) → (𝐹:(Base‘𝑅)⟶(Base‘𝑆) ↔ 𝐹:(Base‘(oppr‘𝑅))⟶(Base‘(oppr‘𝑆)))) | 
| 70 | 7, 59 | oppraddg 13632 | 
. . . . . . . . . . . 12
⊢ (𝑅 ∈ Ring →
(+g‘𝑅) =
(+g‘(oppr‘𝑅))) | 
| 71 | 6, 70 | syl 14 | 
. . . . . . . . . . 11
⊢ (𝐹 ∈ (𝑅 RingHom 𝑆) → (+g‘𝑅) =
(+g‘(oppr‘𝑅))) | 
| 72 | 71 | oveqd 5939 | 
. . . . . . . . . 10
⊢ (𝐹 ∈ (𝑅 RingHom 𝑆) → (𝑥(+g‘𝑅)𝑦) = (𝑥(+g‘(oppr‘𝑅))𝑦)) | 
| 73 | 72 | fveq2d 5562 | 
. . . . . . . . 9
⊢ (𝐹 ∈ (𝑅 RingHom 𝑆) → (𝐹‘(𝑥(+g‘𝑅)𝑦)) = (𝐹‘(𝑥(+g‘(oppr‘𝑅))𝑦))) | 
| 74 | 12, 60 | oppraddg 13632 | 
. . . . . . . . . . 11
⊢ (𝑆 ∈ Ring →
(+g‘𝑆) =
(+g‘(oppr‘𝑆))) | 
| 75 | 11, 74 | syl 14 | 
. . . . . . . . . 10
⊢ (𝐹 ∈ (𝑅 RingHom 𝑆) → (+g‘𝑆) =
(+g‘(oppr‘𝑆))) | 
| 76 | 75 | oveqd 5939 | 
. . . . . . . . 9
⊢ (𝐹 ∈ (𝑅 RingHom 𝑆) → ((𝐹‘𝑥)(+g‘𝑆)(𝐹‘𝑦)) = ((𝐹‘𝑥)(+g‘(oppr‘𝑆))(𝐹‘𝑦))) | 
| 77 | 73, 76 | eqeq12d 2211 | 
. . . . . . . 8
⊢ (𝐹 ∈ (𝑅 RingHom 𝑆) → ((𝐹‘(𝑥(+g‘𝑅)𝑦)) = ((𝐹‘𝑥)(+g‘𝑆)(𝐹‘𝑦)) ↔ (𝐹‘(𝑥(+g‘(oppr‘𝑅))𝑦)) = ((𝐹‘𝑥)(+g‘(oppr‘𝑆))(𝐹‘𝑦)))) | 
| 78 | 31, 77 | raleqbidv 2709 | 
. . . . . . 7
⊢ (𝐹 ∈ (𝑅 RingHom 𝑆) → (∀𝑦 ∈ (Base‘𝑅)(𝐹‘(𝑥(+g‘𝑅)𝑦)) = ((𝐹‘𝑥)(+g‘𝑆)(𝐹‘𝑦)) ↔ ∀𝑦 ∈
(Base‘(oppr‘𝑅))(𝐹‘(𝑥(+g‘(oppr‘𝑅))𝑦)) = ((𝐹‘𝑥)(+g‘(oppr‘𝑆))(𝐹‘𝑦)))) | 
| 79 | 31, 78 | raleqbidv 2709 | 
. . . . . 6
⊢ (𝐹 ∈ (𝑅 RingHom 𝑆) → (∀𝑥 ∈ (Base‘𝑅)∀𝑦 ∈ (Base‘𝑅)(𝐹‘(𝑥(+g‘𝑅)𝑦)) = ((𝐹‘𝑥)(+g‘𝑆)(𝐹‘𝑦)) ↔ ∀𝑥 ∈
(Base‘(oppr‘𝑅))∀𝑦 ∈
(Base‘(oppr‘𝑅))(𝐹‘(𝑥(+g‘(oppr‘𝑅))𝑦)) = ((𝐹‘𝑥)(+g‘(oppr‘𝑆))(𝐹‘𝑦)))) | 
| 80 | 69, 79 | anbi12d 473 | 
. . . . 5
⊢ (𝐹 ∈ (𝑅 RingHom 𝑆) → ((𝐹:(Base‘𝑅)⟶(Base‘𝑆) ∧ ∀𝑥 ∈ (Base‘𝑅)∀𝑦 ∈ (Base‘𝑅)(𝐹‘(𝑥(+g‘𝑅)𝑦)) = ((𝐹‘𝑥)(+g‘𝑆)(𝐹‘𝑦))) ↔ (𝐹:(Base‘(oppr‘𝑅))⟶(Base‘(oppr‘𝑆)) ∧ ∀𝑥 ∈ (Base‘(oppr‘𝑅))∀𝑦 ∈ (Base‘(oppr‘𝑅))(𝐹‘(𝑥(+g‘(oppr‘𝑅))𝑦)) = ((𝐹‘𝑥)(+g‘(oppr‘𝑆))(𝐹‘𝑦))))) | 
| 81 | 80 | anbi2d 464 | 
. . . 4
⊢ (𝐹 ∈ (𝑅 RingHom 𝑆) →
((((oppr‘𝑅) ∈ Grp ∧
(oppr‘𝑆) ∈ Grp) ∧ (𝐹:(Base‘𝑅)⟶(Base‘𝑆) ∧ ∀𝑥 ∈ (Base‘𝑅)∀𝑦 ∈ (Base‘𝑅)(𝐹‘(𝑥(+g‘𝑅)𝑦)) = ((𝐹‘𝑥)(+g‘𝑆)(𝐹‘𝑦)))) ↔
(((oppr‘𝑅) ∈ Grp ∧
(oppr‘𝑆) ∈ Grp) ∧ (𝐹:(Base‘(oppr‘𝑅))⟶(Base‘(oppr‘𝑆)) ∧ ∀𝑥 ∈ (Base‘(oppr‘𝑅))∀𝑦 ∈ (Base‘(oppr‘𝑅))(𝐹‘(𝑥(+g‘(oppr‘𝑅))𝑦)) = ((𝐹‘𝑥)(+g‘(oppr‘𝑆))(𝐹‘𝑦)))))) | 
| 82 | 66, 81 | mpbid 147 | 
. . 3
⊢ (𝐹 ∈ (𝑅 RingHom 𝑆) →
(((oppr‘𝑅) ∈ Grp ∧
(oppr‘𝑆) ∈ Grp) ∧ (𝐹:(Base‘(oppr‘𝑅))⟶(Base‘(oppr‘𝑆)) ∧ ∀𝑥 ∈ (Base‘(oppr‘𝑅))∀𝑦 ∈ (Base‘(oppr‘𝑅))(𝐹‘(𝑥(+g‘(oppr‘𝑅))𝑦)) = ((𝐹‘𝑥)(+g‘(oppr‘𝑆))(𝐹‘𝑦))))) | 
| 83 |   | eqid 2196 | 
. . . 4
⊢
(Base‘(oppr‘𝑆)) =
(Base‘(oppr‘𝑆)) | 
| 84 |   | eqid 2196 | 
. . . 4
⊢
(+g‘(oppr‘𝑅)) =
(+g‘(oppr‘𝑅)) | 
| 85 |   | eqid 2196 | 
. . . 4
⊢
(+g‘(oppr‘𝑆)) =
(+g‘(oppr‘𝑆)) | 
| 86 | 1, 83, 84, 85 | isghm 13373 | 
. . 3
⊢ (𝐹 ∈
((oppr‘𝑅) GrpHom (oppr‘𝑆)) ↔
(((oppr‘𝑅) ∈ Grp ∧
(oppr‘𝑆) ∈ Grp) ∧ (𝐹:(Base‘(oppr‘𝑅))⟶(Base‘(oppr‘𝑆)) ∧ ∀𝑥 ∈ (Base‘(oppr‘𝑅))∀𝑦 ∈ (Base‘(oppr‘𝑅))(𝐹‘(𝑥(+g‘(oppr‘𝑅))𝑦)) = ((𝐹‘𝑥)(+g‘(oppr‘𝑆))(𝐹‘𝑦))))) | 
| 87 | 82, 86 | sylibr 134 | 
. 2
⊢ (𝐹 ∈ (𝑅 RingHom 𝑆) → 𝐹 ∈ ((oppr‘𝑅) GrpHom
(oppr‘𝑆))) | 
| 88 | 1, 2, 3, 4, 5, 10,
15, 26, 52, 87 | isrhm2d 13721 | 
1
⊢ (𝐹 ∈ (𝑅 RingHom 𝑆) → 𝐹 ∈ ((oppr‘𝑅) RingHom
(oppr‘𝑆))) |