Proof of Theorem grpinvssd
| Step | Hyp | Ref
 | Expression | 
| 1 |   | grpidssd.s | 
. . . . . 6
⊢ (𝜑 → 𝑆 ∈ Grp) | 
| 2 |   | grpidssd.b | 
. . . . . . 7
⊢ 𝐵 = (Base‘𝑆) | 
| 3 |   | eqid 2196 | 
. . . . . . 7
⊢
(invg‘𝑆) = (invg‘𝑆) | 
| 4 | 2, 3 | grpinvcl 13180 | 
. . . . . 6
⊢ ((𝑆 ∈ Grp ∧ 𝑋 ∈ 𝐵) → ((invg‘𝑆)‘𝑋) ∈ 𝐵) | 
| 5 | 1, 4 | sylan 283 | 
. . . . 5
⊢ ((𝜑 ∧ 𝑋 ∈ 𝐵) → ((invg‘𝑆)‘𝑋) ∈ 𝐵) | 
| 6 |   | simpr 110 | 
. . . . 5
⊢ ((𝜑 ∧ 𝑋 ∈ 𝐵) → 𝑋 ∈ 𝐵) | 
| 7 |   | grpidssd.o | 
. . . . . 6
⊢ (𝜑 → ∀𝑥 ∈ 𝐵 ∀𝑦 ∈ 𝐵 (𝑥(+g‘𝑀)𝑦) = (𝑥(+g‘𝑆)𝑦)) | 
| 8 | 7 | adantr 276 | 
. . . . 5
⊢ ((𝜑 ∧ 𝑋 ∈ 𝐵) → ∀𝑥 ∈ 𝐵 ∀𝑦 ∈ 𝐵 (𝑥(+g‘𝑀)𝑦) = (𝑥(+g‘𝑆)𝑦)) | 
| 9 |   | oveq1 5929 | 
. . . . . . 7
⊢ (𝑥 = ((invg‘𝑆)‘𝑋) → (𝑥(+g‘𝑀)𝑦) = (((invg‘𝑆)‘𝑋)(+g‘𝑀)𝑦)) | 
| 10 |   | oveq1 5929 | 
. . . . . . 7
⊢ (𝑥 = ((invg‘𝑆)‘𝑋) → (𝑥(+g‘𝑆)𝑦) = (((invg‘𝑆)‘𝑋)(+g‘𝑆)𝑦)) | 
| 11 | 9, 10 | eqeq12d 2211 | 
. . . . . 6
⊢ (𝑥 = ((invg‘𝑆)‘𝑋) → ((𝑥(+g‘𝑀)𝑦) = (𝑥(+g‘𝑆)𝑦) ↔ (((invg‘𝑆)‘𝑋)(+g‘𝑀)𝑦) = (((invg‘𝑆)‘𝑋)(+g‘𝑆)𝑦))) | 
| 12 |   | oveq2 5930 | 
. . . . . . 7
⊢ (𝑦 = 𝑋 → (((invg‘𝑆)‘𝑋)(+g‘𝑀)𝑦) = (((invg‘𝑆)‘𝑋)(+g‘𝑀)𝑋)) | 
| 13 |   | oveq2 5930 | 
. . . . . . 7
⊢ (𝑦 = 𝑋 → (((invg‘𝑆)‘𝑋)(+g‘𝑆)𝑦) = (((invg‘𝑆)‘𝑋)(+g‘𝑆)𝑋)) | 
| 14 | 12, 13 | eqeq12d 2211 | 
. . . . . 6
⊢ (𝑦 = 𝑋 → ((((invg‘𝑆)‘𝑋)(+g‘𝑀)𝑦) = (((invg‘𝑆)‘𝑋)(+g‘𝑆)𝑦) ↔ (((invg‘𝑆)‘𝑋)(+g‘𝑀)𝑋) = (((invg‘𝑆)‘𝑋)(+g‘𝑆)𝑋))) | 
| 15 | 11, 14 | rspc2va 2882 | 
. . . . 5
⊢
(((((invg‘𝑆)‘𝑋) ∈ 𝐵 ∧ 𝑋 ∈ 𝐵) ∧ ∀𝑥 ∈ 𝐵 ∀𝑦 ∈ 𝐵 (𝑥(+g‘𝑀)𝑦) = (𝑥(+g‘𝑆)𝑦)) → (((invg‘𝑆)‘𝑋)(+g‘𝑀)𝑋) = (((invg‘𝑆)‘𝑋)(+g‘𝑆)𝑋)) | 
| 16 | 5, 6, 8, 15 | syl21anc 1248 | 
. . . 4
⊢ ((𝜑 ∧ 𝑋 ∈ 𝐵) → (((invg‘𝑆)‘𝑋)(+g‘𝑀)𝑋) = (((invg‘𝑆)‘𝑋)(+g‘𝑆)𝑋)) | 
| 17 |   | eqid 2196 | 
. . . . . 6
⊢
(+g‘𝑆) = (+g‘𝑆) | 
| 18 |   | eqid 2196 | 
. . . . . 6
⊢
(0g‘𝑆) = (0g‘𝑆) | 
| 19 | 2, 17, 18, 3 | grplinv 13182 | 
. . . . 5
⊢ ((𝑆 ∈ Grp ∧ 𝑋 ∈ 𝐵) → (((invg‘𝑆)‘𝑋)(+g‘𝑆)𝑋) = (0g‘𝑆)) | 
| 20 | 1, 19 | sylan 283 | 
. . . 4
⊢ ((𝜑 ∧ 𝑋 ∈ 𝐵) → (((invg‘𝑆)‘𝑋)(+g‘𝑆)𝑋) = (0g‘𝑆)) | 
| 21 |   | grpidssd.m | 
. . . . . 6
⊢ (𝜑 → 𝑀 ∈ Grp) | 
| 22 |   | grpidssd.c | 
. . . . . . 7
⊢ (𝜑 → 𝐵 ⊆ (Base‘𝑀)) | 
| 23 | 22 | sselda 3183 | 
. . . . . 6
⊢ ((𝜑 ∧ 𝑋 ∈ 𝐵) → 𝑋 ∈ (Base‘𝑀)) | 
| 24 |   | eqid 2196 | 
. . . . . . 7
⊢
(Base‘𝑀) =
(Base‘𝑀) | 
| 25 |   | eqid 2196 | 
. . . . . . 7
⊢
(+g‘𝑀) = (+g‘𝑀) | 
| 26 |   | eqid 2196 | 
. . . . . . 7
⊢
(0g‘𝑀) = (0g‘𝑀) | 
| 27 |   | eqid 2196 | 
. . . . . . 7
⊢
(invg‘𝑀) = (invg‘𝑀) | 
| 28 | 24, 25, 26, 27 | grplinv 13182 | 
. . . . . 6
⊢ ((𝑀 ∈ Grp ∧ 𝑋 ∈ (Base‘𝑀)) →
(((invg‘𝑀)‘𝑋)(+g‘𝑀)𝑋) = (0g‘𝑀)) | 
| 29 | 21, 23, 28 | syl2an2r 595 | 
. . . . 5
⊢ ((𝜑 ∧ 𝑋 ∈ 𝐵) → (((invg‘𝑀)‘𝑋)(+g‘𝑀)𝑋) = (0g‘𝑀)) | 
| 30 | 21, 1, 2, 22, 7 | grpidssd 13208 | 
. . . . . 6
⊢ (𝜑 → (0g‘𝑀) = (0g‘𝑆)) | 
| 31 | 30 | adantr 276 | 
. . . . 5
⊢ ((𝜑 ∧ 𝑋 ∈ 𝐵) → (0g‘𝑀) = (0g‘𝑆)) | 
| 32 | 29, 31 | eqtr2d 2230 | 
. . . 4
⊢ ((𝜑 ∧ 𝑋 ∈ 𝐵) → (0g‘𝑆) =
(((invg‘𝑀)‘𝑋)(+g‘𝑀)𝑋)) | 
| 33 | 16, 20, 32 | 3eqtrd 2233 | 
. . 3
⊢ ((𝜑 ∧ 𝑋 ∈ 𝐵) → (((invg‘𝑆)‘𝑋)(+g‘𝑀)𝑋) = (((invg‘𝑀)‘𝑋)(+g‘𝑀)𝑋)) | 
| 34 | 21 | adantr 276 | 
. . . 4
⊢ ((𝜑 ∧ 𝑋 ∈ 𝐵) → 𝑀 ∈ Grp) | 
| 35 | 22 | adantr 276 | 
. . . . 5
⊢ ((𝜑 ∧ 𝑋 ∈ 𝐵) → 𝐵 ⊆ (Base‘𝑀)) | 
| 36 | 35, 5 | sseldd 3184 | 
. . . 4
⊢ ((𝜑 ∧ 𝑋 ∈ 𝐵) → ((invg‘𝑆)‘𝑋) ∈ (Base‘𝑀)) | 
| 37 | 24, 27 | grpinvcl 13180 | 
. . . . 5
⊢ ((𝑀 ∈ Grp ∧ 𝑋 ∈ (Base‘𝑀)) →
((invg‘𝑀)‘𝑋) ∈ (Base‘𝑀)) | 
| 38 | 21, 23, 37 | syl2an2r 595 | 
. . . 4
⊢ ((𝜑 ∧ 𝑋 ∈ 𝐵) → ((invg‘𝑀)‘𝑋) ∈ (Base‘𝑀)) | 
| 39 | 24, 25 | grprcan 13169 | 
. . . 4
⊢ ((𝑀 ∈ Grp ∧
(((invg‘𝑆)‘𝑋) ∈ (Base‘𝑀) ∧ ((invg‘𝑀)‘𝑋) ∈ (Base‘𝑀) ∧ 𝑋 ∈ (Base‘𝑀))) → ((((invg‘𝑆)‘𝑋)(+g‘𝑀)𝑋) = (((invg‘𝑀)‘𝑋)(+g‘𝑀)𝑋) ↔ ((invg‘𝑆)‘𝑋) = ((invg‘𝑀)‘𝑋))) | 
| 40 | 34, 36, 38, 23, 39 | syl13anc 1251 | 
. . 3
⊢ ((𝜑 ∧ 𝑋 ∈ 𝐵) → ((((invg‘𝑆)‘𝑋)(+g‘𝑀)𝑋) = (((invg‘𝑀)‘𝑋)(+g‘𝑀)𝑋) ↔ ((invg‘𝑆)‘𝑋) = ((invg‘𝑀)‘𝑋))) | 
| 41 | 33, 40 | mpbid 147 | 
. 2
⊢ ((𝜑 ∧ 𝑋 ∈ 𝐵) → ((invg‘𝑆)‘𝑋) = ((invg‘𝑀)‘𝑋)) | 
| 42 | 41 | ex 115 | 
1
⊢ (𝜑 → (𝑋 ∈ 𝐵 → ((invg‘𝑆)‘𝑋) = ((invg‘𝑀)‘𝑋))) |