| Step | Hyp | Ref | Expression | 
|---|
| 1 |  | iscyg.1 | . . . . 5
⊢ 𝐵 = (Base‘𝐺) | 
| 2 |  | iscyg.2 | . . . . 5
⊢  · =
(.g‘𝐺) | 
| 3 |  | iscyg3.e | . . . . 5
⊢ 𝐸 = {𝑥 ∈ 𝐵 ∣ ran (𝑛 ∈ ℤ ↦ (𝑛 · 𝑥)) = 𝐵} | 
| 4 | 1, 2, 3 | iscyggen2 19899 | . . . 4
⊢ (𝐺 ∈ Grp → (𝑋 ∈ 𝐸 ↔ (𝑋 ∈ 𝐵 ∧ ∀𝑦 ∈ 𝐵 ∃𝑛 ∈ ℤ 𝑦 = (𝑛 · 𝑋)))) | 
| 5 | 4 | simprbda 498 | . . 3
⊢ ((𝐺 ∈ Grp ∧ 𝑋 ∈ 𝐸) → 𝑋 ∈ 𝐵) | 
| 6 |  | cyggeninv.n | . . . 4
⊢ 𝑁 = (invg‘𝐺) | 
| 7 | 1, 6 | grpinvcl 19005 | . . 3
⊢ ((𝐺 ∈ Grp ∧ 𝑋 ∈ 𝐵) → (𝑁‘𝑋) ∈ 𝐵) | 
| 8 | 5, 7 | syldan 591 | . 2
⊢ ((𝐺 ∈ Grp ∧ 𝑋 ∈ 𝐸) → (𝑁‘𝑋) ∈ 𝐵) | 
| 9 | 4 | simplbda 499 | . . 3
⊢ ((𝐺 ∈ Grp ∧ 𝑋 ∈ 𝐸) → ∀𝑦 ∈ 𝐵 ∃𝑛 ∈ ℤ 𝑦 = (𝑛 · 𝑋)) | 
| 10 |  | oveq1 7438 | . . . . . . 7
⊢ (𝑛 = 𝑚 → (𝑛 · 𝑋) = (𝑚 · 𝑋)) | 
| 11 | 10 | eqeq2d 2748 | . . . . . 6
⊢ (𝑛 = 𝑚 → (𝑦 = (𝑛 · 𝑋) ↔ 𝑦 = (𝑚 · 𝑋))) | 
| 12 | 11 | cbvrexvw 3238 | . . . . 5
⊢
(∃𝑛 ∈
ℤ 𝑦 = (𝑛 · 𝑋) ↔ ∃𝑚 ∈ ℤ 𝑦 = (𝑚 · 𝑋)) | 
| 13 |  | znegcl 12652 | . . . . . . . . 9
⊢ (𝑚 ∈ ℤ → -𝑚 ∈
ℤ) | 
| 14 | 13 | adantl 481 | . . . . . . . 8
⊢ ((((𝐺 ∈ Grp ∧ 𝑋 ∈ 𝐸) ∧ 𝑦 ∈ 𝐵) ∧ 𝑚 ∈ ℤ) → -𝑚 ∈ ℤ) | 
| 15 |  | simpr 484 | . . . . . . . . . . . 12
⊢ ((((𝐺 ∈ Grp ∧ 𝑋 ∈ 𝐸) ∧ 𝑦 ∈ 𝐵) ∧ 𝑚 ∈ ℤ) → 𝑚 ∈ ℤ) | 
| 16 | 15 | zcnd 12723 | . . . . . . . . . . 11
⊢ ((((𝐺 ∈ Grp ∧ 𝑋 ∈ 𝐸) ∧ 𝑦 ∈ 𝐵) ∧ 𝑚 ∈ ℤ) → 𝑚 ∈ ℂ) | 
| 17 | 16 | negnegd 11611 | . . . . . . . . . 10
⊢ ((((𝐺 ∈ Grp ∧ 𝑋 ∈ 𝐸) ∧ 𝑦 ∈ 𝐵) ∧ 𝑚 ∈ ℤ) → --𝑚 = 𝑚) | 
| 18 | 17 | oveq1d 7446 | . . . . . . . . 9
⊢ ((((𝐺 ∈ Grp ∧ 𝑋 ∈ 𝐸) ∧ 𝑦 ∈ 𝐵) ∧ 𝑚 ∈ ℤ) → (--𝑚 · 𝑋) = (𝑚 · 𝑋)) | 
| 19 |  | simplll 775 | . . . . . . . . . 10
⊢ ((((𝐺 ∈ Grp ∧ 𝑋 ∈ 𝐸) ∧ 𝑦 ∈ 𝐵) ∧ 𝑚 ∈ ℤ) → 𝐺 ∈ Grp) | 
| 20 | 5 | ad2antrr 726 | . . . . . . . . . 10
⊢ ((((𝐺 ∈ Grp ∧ 𝑋 ∈ 𝐸) ∧ 𝑦 ∈ 𝐵) ∧ 𝑚 ∈ ℤ) → 𝑋 ∈ 𝐵) | 
| 21 | 1, 2, 6 | mulgneg2 19126 | . . . . . . . . . 10
⊢ ((𝐺 ∈ Grp ∧ -𝑚 ∈ ℤ ∧ 𝑋 ∈ 𝐵) → (--𝑚 · 𝑋) = (-𝑚 · (𝑁‘𝑋))) | 
| 22 | 19, 14, 20, 21 | syl3anc 1373 | . . . . . . . . 9
⊢ ((((𝐺 ∈ Grp ∧ 𝑋 ∈ 𝐸) ∧ 𝑦 ∈ 𝐵) ∧ 𝑚 ∈ ℤ) → (--𝑚 · 𝑋) = (-𝑚 · (𝑁‘𝑋))) | 
| 23 | 18, 22 | eqtr3d 2779 | . . . . . . . 8
⊢ ((((𝐺 ∈ Grp ∧ 𝑋 ∈ 𝐸) ∧ 𝑦 ∈ 𝐵) ∧ 𝑚 ∈ ℤ) → (𝑚 · 𝑋) = (-𝑚 · (𝑁‘𝑋))) | 
| 24 |  | oveq1 7438 | . . . . . . . . 9
⊢ (𝑛 = -𝑚 → (𝑛 · (𝑁‘𝑋)) = (-𝑚 · (𝑁‘𝑋))) | 
| 25 | 24 | rspceeqv 3645 | . . . . . . . 8
⊢ ((-𝑚 ∈ ℤ ∧ (𝑚 · 𝑋) = (-𝑚 · (𝑁‘𝑋))) → ∃𝑛 ∈ ℤ (𝑚 · 𝑋) = (𝑛 · (𝑁‘𝑋))) | 
| 26 | 14, 23, 25 | syl2anc 584 | . . . . . . 7
⊢ ((((𝐺 ∈ Grp ∧ 𝑋 ∈ 𝐸) ∧ 𝑦 ∈ 𝐵) ∧ 𝑚 ∈ ℤ) → ∃𝑛 ∈ ℤ (𝑚 · 𝑋) = (𝑛 · (𝑁‘𝑋))) | 
| 27 |  | eqeq1 2741 | . . . . . . . 8
⊢ (𝑦 = (𝑚 · 𝑋) → (𝑦 = (𝑛 · (𝑁‘𝑋)) ↔ (𝑚 · 𝑋) = (𝑛 · (𝑁‘𝑋)))) | 
| 28 | 27 | rexbidv 3179 | . . . . . . 7
⊢ (𝑦 = (𝑚 · 𝑋) → (∃𝑛 ∈ ℤ 𝑦 = (𝑛 · (𝑁‘𝑋)) ↔ ∃𝑛 ∈ ℤ (𝑚 · 𝑋) = (𝑛 · (𝑁‘𝑋)))) | 
| 29 | 26, 28 | syl5ibrcom 247 | . . . . . 6
⊢ ((((𝐺 ∈ Grp ∧ 𝑋 ∈ 𝐸) ∧ 𝑦 ∈ 𝐵) ∧ 𝑚 ∈ ℤ) → (𝑦 = (𝑚 · 𝑋) → ∃𝑛 ∈ ℤ 𝑦 = (𝑛 · (𝑁‘𝑋)))) | 
| 30 | 29 | rexlimdva 3155 | . . . . 5
⊢ (((𝐺 ∈ Grp ∧ 𝑋 ∈ 𝐸) ∧ 𝑦 ∈ 𝐵) → (∃𝑚 ∈ ℤ 𝑦 = (𝑚 · 𝑋) → ∃𝑛 ∈ ℤ 𝑦 = (𝑛 · (𝑁‘𝑋)))) | 
| 31 | 12, 30 | biimtrid 242 | . . . 4
⊢ (((𝐺 ∈ Grp ∧ 𝑋 ∈ 𝐸) ∧ 𝑦 ∈ 𝐵) → (∃𝑛 ∈ ℤ 𝑦 = (𝑛 · 𝑋) → ∃𝑛 ∈ ℤ 𝑦 = (𝑛 · (𝑁‘𝑋)))) | 
| 32 | 31 | ralimdva 3167 | . . 3
⊢ ((𝐺 ∈ Grp ∧ 𝑋 ∈ 𝐸) → (∀𝑦 ∈ 𝐵 ∃𝑛 ∈ ℤ 𝑦 = (𝑛 · 𝑋) → ∀𝑦 ∈ 𝐵 ∃𝑛 ∈ ℤ 𝑦 = (𝑛 · (𝑁‘𝑋)))) | 
| 33 | 9, 32 | mpd 15 | . 2
⊢ ((𝐺 ∈ Grp ∧ 𝑋 ∈ 𝐸) → ∀𝑦 ∈ 𝐵 ∃𝑛 ∈ ℤ 𝑦 = (𝑛 · (𝑁‘𝑋))) | 
| 34 | 1, 2, 3 | iscyggen2 19899 | . . 3
⊢ (𝐺 ∈ Grp → ((𝑁‘𝑋) ∈ 𝐸 ↔ ((𝑁‘𝑋) ∈ 𝐵 ∧ ∀𝑦 ∈ 𝐵 ∃𝑛 ∈ ℤ 𝑦 = (𝑛 · (𝑁‘𝑋))))) | 
| 35 | 34 | adantr 480 | . 2
⊢ ((𝐺 ∈ Grp ∧ 𝑋 ∈ 𝐸) → ((𝑁‘𝑋) ∈ 𝐸 ↔ ((𝑁‘𝑋) ∈ 𝐵 ∧ ∀𝑦 ∈ 𝐵 ∃𝑛 ∈ ℤ 𝑦 = (𝑛 · (𝑁‘𝑋))))) | 
| 36 | 8, 33, 35 | mpbir2and 713 | 1
⊢ ((𝐺 ∈ Grp ∧ 𝑋 ∈ 𝐸) → (𝑁‘𝑋) ∈ 𝐸) |