| Step | Hyp | Ref
 | Expression | 
| 1 |   | mulgpropd.b1 | 
. . . . . . 7
⊢ (𝜑 → 𝐵 = (Base‘𝐺)) | 
| 2 |   | mulgpropd.b2 | 
. . . . . . 7
⊢ (𝜑 → 𝐵 = (Base‘𝐻)) | 
| 3 |   | mulgpropdg.g | 
. . . . . . 7
⊢ (𝜑 → 𝐺 ∈ 𝑉) | 
| 4 |   | mulgpropdg.h | 
. . . . . . 7
⊢ (𝜑 → 𝐻 ∈ 𝑊) | 
| 5 |   | mulgpropd.i | 
. . . . . . . . . 10
⊢ (𝜑 → 𝐵 ⊆ 𝐾) | 
| 6 |   | ssel 3177 | 
. . . . . . . . . . 11
⊢ (𝐵 ⊆ 𝐾 → (𝑥 ∈ 𝐵 → 𝑥 ∈ 𝐾)) | 
| 7 |   | ssel 3177 | 
. . . . . . . . . . 11
⊢ (𝐵 ⊆ 𝐾 → (𝑦 ∈ 𝐵 → 𝑦 ∈ 𝐾)) | 
| 8 | 6, 7 | anim12d 335 | 
. . . . . . . . . 10
⊢ (𝐵 ⊆ 𝐾 → ((𝑥 ∈ 𝐵 ∧ 𝑦 ∈ 𝐵) → (𝑥 ∈ 𝐾 ∧ 𝑦 ∈ 𝐾))) | 
| 9 | 5, 8 | syl 14 | 
. . . . . . . . 9
⊢ (𝜑 → ((𝑥 ∈ 𝐵 ∧ 𝑦 ∈ 𝐵) → (𝑥 ∈ 𝐾 ∧ 𝑦 ∈ 𝐾))) | 
| 10 | 9 | imp 124 | 
. . . . . . . 8
⊢ ((𝜑 ∧ (𝑥 ∈ 𝐵 ∧ 𝑦 ∈ 𝐵)) → (𝑥 ∈ 𝐾 ∧ 𝑦 ∈ 𝐾)) | 
| 11 |   | mulgpropd.e | 
. . . . . . . 8
⊢ ((𝜑 ∧ (𝑥 ∈ 𝐾 ∧ 𝑦 ∈ 𝐾)) → (𝑥(+g‘𝐺)𝑦) = (𝑥(+g‘𝐻)𝑦)) | 
| 12 | 10, 11 | syldan 282 | 
. . . . . . 7
⊢ ((𝜑 ∧ (𝑥 ∈ 𝐵 ∧ 𝑦 ∈ 𝐵)) → (𝑥(+g‘𝐺)𝑦) = (𝑥(+g‘𝐻)𝑦)) | 
| 13 | 1, 2, 3, 4, 12 | grpidpropdg 13017 | 
. . . . . 6
⊢ (𝜑 → (0g‘𝐺) = (0g‘𝐻)) | 
| 14 | 13 | 3ad2ant1 1020 | 
. . . . 5
⊢ ((𝜑 ∧ 𝑎 ∈ ℤ ∧ 𝑏 ∈ 𝐵) → (0g‘𝐺) = (0g‘𝐻)) | 
| 15 |   | 1zzd 9353 | 
. . . . . . . 8
⊢ ((𝜑 ∧ 𝑎 ∈ ℤ ∧ 𝑏 ∈ 𝐵) → 1 ∈ ℤ) | 
| 16 |   | nnuz 9637 | 
. . . . . . . . 9
⊢ ℕ =
(ℤ≥‘1) | 
| 17 | 5 | 3ad2ant1 1020 | 
. . . . . . . . . 10
⊢ ((𝜑 ∧ 𝑎 ∈ ℤ ∧ 𝑏 ∈ 𝐵) → 𝐵 ⊆ 𝐾) | 
| 18 |   | simp3 1001 | 
. . . . . . . . . 10
⊢ ((𝜑 ∧ 𝑎 ∈ ℤ ∧ 𝑏 ∈ 𝐵) → 𝑏 ∈ 𝐵) | 
| 19 | 17, 18 | sseldd 3184 | 
. . . . . . . . 9
⊢ ((𝜑 ∧ 𝑎 ∈ ℤ ∧ 𝑏 ∈ 𝐵) → 𝑏 ∈ 𝐾) | 
| 20 | 16, 19 | ialgrlemconst 12211 | 
. . . . . . . 8
⊢ (((𝜑 ∧ 𝑎 ∈ ℤ ∧ 𝑏 ∈ 𝐵) ∧ 𝑥 ∈ (ℤ≥‘1))
→ ((ℕ × {𝑏})‘𝑥) ∈ 𝐾) | 
| 21 |   | mulgpropd.k | 
. . . . . . . . 9
⊢ ((𝜑 ∧ (𝑥 ∈ 𝐾 ∧ 𝑦 ∈ 𝐾)) → (𝑥(+g‘𝐺)𝑦) ∈ 𝐾) | 
| 22 | 21 | 3ad2antl1 1161 | 
. . . . . . . 8
⊢ (((𝜑 ∧ 𝑎 ∈ ℤ ∧ 𝑏 ∈ 𝐵) ∧ (𝑥 ∈ 𝐾 ∧ 𝑦 ∈ 𝐾)) → (𝑥(+g‘𝐺)𝑦) ∈ 𝐾) | 
| 23 | 11 | 3ad2antl1 1161 | 
. . . . . . . 8
⊢ (((𝜑 ∧ 𝑎 ∈ ℤ ∧ 𝑏 ∈ 𝐵) ∧ (𝑥 ∈ 𝐾 ∧ 𝑦 ∈ 𝐾)) → (𝑥(+g‘𝐺)𝑦) = (𝑥(+g‘𝐻)𝑦)) | 
| 24 | 15, 20, 22, 23 | seqfeq3 10621 | 
. . . . . . 7
⊢ ((𝜑 ∧ 𝑎 ∈ ℤ ∧ 𝑏 ∈ 𝐵) → seq1((+g‘𝐺), (ℕ × {𝑏})) =
seq1((+g‘𝐻), (ℕ × {𝑏}))) | 
| 25 | 24 | fveq1d 5560 | 
. . . . . 6
⊢ ((𝜑 ∧ 𝑎 ∈ ℤ ∧ 𝑏 ∈ 𝐵) → (seq1((+g‘𝐺), (ℕ × {𝑏}))‘𝑎) = (seq1((+g‘𝐻), (ℕ × {𝑏}))‘𝑎)) | 
| 26 | 1, 2, 3, 4, 12 | grpinvpropdg 13207 | 
. . . . . . . 8
⊢ (𝜑 →
(invg‘𝐺) =
(invg‘𝐻)) | 
| 27 | 26 | 3ad2ant1 1020 | 
. . . . . . 7
⊢ ((𝜑 ∧ 𝑎 ∈ ℤ ∧ 𝑏 ∈ 𝐵) → (invg‘𝐺) = (invg‘𝐻)) | 
| 28 | 24 | fveq1d 5560 | 
. . . . . . 7
⊢ ((𝜑 ∧ 𝑎 ∈ ℤ ∧ 𝑏 ∈ 𝐵) → (seq1((+g‘𝐺), (ℕ × {𝑏}))‘-𝑎) = (seq1((+g‘𝐻), (ℕ × {𝑏}))‘-𝑎)) | 
| 29 | 27, 28 | fveq12d 5565 | 
. . . . . 6
⊢ ((𝜑 ∧ 𝑎 ∈ ℤ ∧ 𝑏 ∈ 𝐵) → ((invg‘𝐺)‘(seq1((+g‘𝐺), (ℕ × {𝑏}))‘-𝑎)) = ((invg‘𝐻)‘(seq1((+g‘𝐻), (ℕ × {𝑏}))‘-𝑎))) | 
| 30 | 25, 29 | ifeq12d 3580 | 
. . . . 5
⊢ ((𝜑 ∧ 𝑎 ∈ ℤ ∧ 𝑏 ∈ 𝐵) → if(0 < 𝑎, (seq1((+g‘𝐺), (ℕ × {𝑏}))‘𝑎), ((invg‘𝐺)‘(seq1((+g‘𝐺), (ℕ × {𝑏}))‘-𝑎))) = if(0 < 𝑎, (seq1((+g‘𝐻), (ℕ × {𝑏}))‘𝑎), ((invg‘𝐻)‘(seq1((+g‘𝐻), (ℕ × {𝑏}))‘-𝑎)))) | 
| 31 | 14, 30 | ifeq12d 3580 | 
. . . 4
⊢ ((𝜑 ∧ 𝑎 ∈ ℤ ∧ 𝑏 ∈ 𝐵) → if(𝑎 = 0, (0g‘𝐺), if(0 < 𝑎, (seq1((+g‘𝐺), (ℕ × {𝑏}))‘𝑎), ((invg‘𝐺)‘(seq1((+g‘𝐺), (ℕ × {𝑏}))‘-𝑎)))) = if(𝑎 = 0, (0g‘𝐻), if(0 < 𝑎, (seq1((+g‘𝐻), (ℕ × {𝑏}))‘𝑎), ((invg‘𝐻)‘(seq1((+g‘𝐻), (ℕ × {𝑏}))‘-𝑎))))) | 
| 32 | 31 | mpoeq3dva 5986 | 
. . 3
⊢ (𝜑 → (𝑎 ∈ ℤ, 𝑏 ∈ 𝐵 ↦ if(𝑎 = 0, (0g‘𝐺), if(0 < 𝑎, (seq1((+g‘𝐺), (ℕ × {𝑏}))‘𝑎), ((invg‘𝐺)‘(seq1((+g‘𝐺), (ℕ × {𝑏}))‘-𝑎))))) = (𝑎 ∈ ℤ, 𝑏 ∈ 𝐵 ↦ if(𝑎 = 0, (0g‘𝐻), if(0 < 𝑎, (seq1((+g‘𝐻), (ℕ × {𝑏}))‘𝑎), ((invg‘𝐻)‘(seq1((+g‘𝐻), (ℕ × {𝑏}))‘-𝑎)))))) | 
| 33 |   | eqidd 2197 | 
. . . 4
⊢ (𝜑 → ℤ =
ℤ) | 
| 34 |   | eqidd 2197 | 
. . . 4
⊢ (𝜑 → if(𝑎 = 0, (0g‘𝐺), if(0 < 𝑎, (seq1((+g‘𝐺), (ℕ × {𝑏}))‘𝑎), ((invg‘𝐺)‘(seq1((+g‘𝐺), (ℕ × {𝑏}))‘-𝑎)))) = if(𝑎 = 0, (0g‘𝐺), if(0 < 𝑎, (seq1((+g‘𝐺), (ℕ × {𝑏}))‘𝑎), ((invg‘𝐺)‘(seq1((+g‘𝐺), (ℕ × {𝑏}))‘-𝑎))))) | 
| 35 | 33, 1, 34 | mpoeq123dv 5984 | 
. . 3
⊢ (𝜑 → (𝑎 ∈ ℤ, 𝑏 ∈ 𝐵 ↦ if(𝑎 = 0, (0g‘𝐺), if(0 < 𝑎, (seq1((+g‘𝐺), (ℕ × {𝑏}))‘𝑎), ((invg‘𝐺)‘(seq1((+g‘𝐺), (ℕ × {𝑏}))‘-𝑎))))) = (𝑎 ∈ ℤ, 𝑏 ∈ (Base‘𝐺) ↦ if(𝑎 = 0, (0g‘𝐺), if(0 < 𝑎, (seq1((+g‘𝐺), (ℕ × {𝑏}))‘𝑎), ((invg‘𝐺)‘(seq1((+g‘𝐺), (ℕ × {𝑏}))‘-𝑎)))))) | 
| 36 |   | eqidd 2197 | 
. . . 4
⊢ (𝜑 → if(𝑎 = 0, (0g‘𝐻), if(0 < 𝑎, (seq1((+g‘𝐻), (ℕ × {𝑏}))‘𝑎), ((invg‘𝐻)‘(seq1((+g‘𝐻), (ℕ × {𝑏}))‘-𝑎)))) = if(𝑎 = 0, (0g‘𝐻), if(0 < 𝑎, (seq1((+g‘𝐻), (ℕ × {𝑏}))‘𝑎), ((invg‘𝐻)‘(seq1((+g‘𝐻), (ℕ × {𝑏}))‘-𝑎))))) | 
| 37 | 33, 2, 36 | mpoeq123dv 5984 | 
. . 3
⊢ (𝜑 → (𝑎 ∈ ℤ, 𝑏 ∈ 𝐵 ↦ if(𝑎 = 0, (0g‘𝐻), if(0 < 𝑎, (seq1((+g‘𝐻), (ℕ × {𝑏}))‘𝑎), ((invg‘𝐻)‘(seq1((+g‘𝐻), (ℕ × {𝑏}))‘-𝑎))))) = (𝑎 ∈ ℤ, 𝑏 ∈ (Base‘𝐻) ↦ if(𝑎 = 0, (0g‘𝐻), if(0 < 𝑎, (seq1((+g‘𝐻), (ℕ × {𝑏}))‘𝑎), ((invg‘𝐻)‘(seq1((+g‘𝐻), (ℕ × {𝑏}))‘-𝑎)))))) | 
| 38 | 32, 35, 37 | 3eqtr3d 2237 | 
. 2
⊢ (𝜑 → (𝑎 ∈ ℤ, 𝑏 ∈ (Base‘𝐺) ↦ if(𝑎 = 0, (0g‘𝐺), if(0 < 𝑎, (seq1((+g‘𝐺), (ℕ × {𝑏}))‘𝑎), ((invg‘𝐺)‘(seq1((+g‘𝐺), (ℕ × {𝑏}))‘-𝑎))))) = (𝑎 ∈ ℤ, 𝑏 ∈ (Base‘𝐻) ↦ if(𝑎 = 0, (0g‘𝐻), if(0 < 𝑎, (seq1((+g‘𝐻), (ℕ × {𝑏}))‘𝑎), ((invg‘𝐻)‘(seq1((+g‘𝐻), (ℕ × {𝑏}))‘-𝑎)))))) | 
| 39 |   | mulgpropdg.m | 
. . 3
⊢ (𝜑 → · =
(.g‘𝐺)) | 
| 40 |   | eqid 2196 | 
. . . . 5
⊢
(Base‘𝐺) =
(Base‘𝐺) | 
| 41 |   | eqid 2196 | 
. . . . 5
⊢
(+g‘𝐺) = (+g‘𝐺) | 
| 42 |   | eqid 2196 | 
. . . . 5
⊢
(0g‘𝐺) = (0g‘𝐺) | 
| 43 |   | eqid 2196 | 
. . . . 5
⊢
(invg‘𝐺) = (invg‘𝐺) | 
| 44 |   | eqid 2196 | 
. . . . 5
⊢
(.g‘𝐺) = (.g‘𝐺) | 
| 45 | 40, 41, 42, 43, 44 | mulgfvalg 13251 | 
. . . 4
⊢ (𝐺 ∈ 𝑉 → (.g‘𝐺) = (𝑎 ∈ ℤ, 𝑏 ∈ (Base‘𝐺) ↦ if(𝑎 = 0, (0g‘𝐺), if(0 < 𝑎, (seq1((+g‘𝐺), (ℕ × {𝑏}))‘𝑎), ((invg‘𝐺)‘(seq1((+g‘𝐺), (ℕ × {𝑏}))‘-𝑎)))))) | 
| 46 | 3, 45 | syl 14 | 
. . 3
⊢ (𝜑 → (.g‘𝐺) = (𝑎 ∈ ℤ, 𝑏 ∈ (Base‘𝐺) ↦ if(𝑎 = 0, (0g‘𝐺), if(0 < 𝑎, (seq1((+g‘𝐺), (ℕ × {𝑏}))‘𝑎), ((invg‘𝐺)‘(seq1((+g‘𝐺), (ℕ × {𝑏}))‘-𝑎)))))) | 
| 47 | 39, 46 | eqtrd 2229 | 
. 2
⊢ (𝜑 → · = (𝑎 ∈ ℤ, 𝑏 ∈ (Base‘𝐺) ↦ if(𝑎 = 0, (0g‘𝐺), if(0 < 𝑎, (seq1((+g‘𝐺), (ℕ × {𝑏}))‘𝑎), ((invg‘𝐺)‘(seq1((+g‘𝐺), (ℕ × {𝑏}))‘-𝑎)))))) | 
| 48 |   | mulgpropdg.n | 
. . 3
⊢ (𝜑 → × =
(.g‘𝐻)) | 
| 49 |   | eqid 2196 | 
. . . . 5
⊢
(Base‘𝐻) =
(Base‘𝐻) | 
| 50 |   | eqid 2196 | 
. . . . 5
⊢
(+g‘𝐻) = (+g‘𝐻) | 
| 51 |   | eqid 2196 | 
. . . . 5
⊢
(0g‘𝐻) = (0g‘𝐻) | 
| 52 |   | eqid 2196 | 
. . . . 5
⊢
(invg‘𝐻) = (invg‘𝐻) | 
| 53 |   | eqid 2196 | 
. . . . 5
⊢
(.g‘𝐻) = (.g‘𝐻) | 
| 54 | 49, 50, 51, 52, 53 | mulgfvalg 13251 | 
. . . 4
⊢ (𝐻 ∈ 𝑊 → (.g‘𝐻) = (𝑎 ∈ ℤ, 𝑏 ∈ (Base‘𝐻) ↦ if(𝑎 = 0, (0g‘𝐻), if(0 < 𝑎, (seq1((+g‘𝐻), (ℕ × {𝑏}))‘𝑎), ((invg‘𝐻)‘(seq1((+g‘𝐻), (ℕ × {𝑏}))‘-𝑎)))))) | 
| 55 | 4, 54 | syl 14 | 
. . 3
⊢ (𝜑 → (.g‘𝐻) = (𝑎 ∈ ℤ, 𝑏 ∈ (Base‘𝐻) ↦ if(𝑎 = 0, (0g‘𝐻), if(0 < 𝑎, (seq1((+g‘𝐻), (ℕ × {𝑏}))‘𝑎), ((invg‘𝐻)‘(seq1((+g‘𝐻), (ℕ × {𝑏}))‘-𝑎)))))) | 
| 56 | 48, 55 | eqtrd 2229 | 
. 2
⊢ (𝜑 → × = (𝑎 ∈ ℤ, 𝑏 ∈ (Base‘𝐻) ↦ if(𝑎 = 0, (0g‘𝐻), if(0 < 𝑎, (seq1((+g‘𝐻), (ℕ × {𝑏}))‘𝑎), ((invg‘𝐻)‘(seq1((+g‘𝐻), (ℕ × {𝑏}))‘-𝑎)))))) | 
| 57 | 38, 47, 56 | 3eqtr4d 2239 | 
1
⊢ (𝜑 → · = ×
) |