| Step | Hyp | Ref | Expression | 
|---|
| 1 |  | eqidd 2738 | . 2
⊢ (𝐷 ∈ 𝑉 → (𝐺 ↾s {𝑥 ∈ 𝐵 ∣ dom (𝑥 ∖ I ) ∈ Fin}) = (𝐺 ↾s {𝑥 ∈ 𝐵 ∣ dom (𝑥 ∖ I ) ∈ Fin})) | 
| 2 |  | eqidd 2738 | . 2
⊢ (𝐷 ∈ 𝑉 → (0g‘𝐺) = (0g‘𝐺)) | 
| 3 |  | eqidd 2738 | . 2
⊢ (𝐷 ∈ 𝑉 → (+g‘𝐺) = (+g‘𝐺)) | 
| 4 |  | ssrab2 4080 | . . . 4
⊢ {𝑥 ∈ 𝐵 ∣ dom (𝑥 ∖ I ) ∈ Fin} ⊆ 𝐵 | 
| 5 |  | symgsssg.b | . . . 4
⊢ 𝐵 = (Base‘𝐺) | 
| 6 | 4, 5 | sseqtri 4032 | . . 3
⊢ {𝑥 ∈ 𝐵 ∣ dom (𝑥 ∖ I ) ∈ Fin} ⊆
(Base‘𝐺) | 
| 7 | 6 | a1i 11 | . 2
⊢ (𝐷 ∈ 𝑉 → {𝑥 ∈ 𝐵 ∣ dom (𝑥 ∖ I ) ∈ Fin} ⊆
(Base‘𝐺)) | 
| 8 |  | difeq1 4119 | . . . . 5
⊢ (𝑥 = (0g‘𝐺) → (𝑥 ∖ I ) = ((0g‘𝐺) ∖ I )) | 
| 9 | 8 | dmeqd 5916 | . . . 4
⊢ (𝑥 = (0g‘𝐺) → dom (𝑥 ∖ I ) = dom
((0g‘𝐺)
∖ I )) | 
| 10 | 9 | eleq1d 2826 | . . 3
⊢ (𝑥 = (0g‘𝐺) → (dom (𝑥 ∖ I ) ∈ Fin ↔
dom ((0g‘𝐺) ∖ I ) ∈ Fin)) | 
| 11 |  | symgsssg.g | . . . . 5
⊢ 𝐺 = (SymGrp‘𝐷) | 
| 12 | 11 | symggrp 19418 | . . . 4
⊢ (𝐷 ∈ 𝑉 → 𝐺 ∈ Grp) | 
| 13 |  | eqid 2737 | . . . . 5
⊢
(0g‘𝐺) = (0g‘𝐺) | 
| 14 | 5, 13 | grpidcl 18983 | . . . 4
⊢ (𝐺 ∈ Grp →
(0g‘𝐺)
∈ 𝐵) | 
| 15 | 12, 14 | syl 17 | . . 3
⊢ (𝐷 ∈ 𝑉 → (0g‘𝐺) ∈ 𝐵) | 
| 16 | 11 | symgid 19419 | . . . . . 6
⊢ (𝐷 ∈ 𝑉 → ( I ↾ 𝐷) = (0g‘𝐺)) | 
| 17 | 16 | difeq1d 4125 | . . . . 5
⊢ (𝐷 ∈ 𝑉 → (( I ↾ 𝐷) ∖ I ) = ((0g‘𝐺) ∖ I )) | 
| 18 | 17 | dmeqd 5916 | . . . 4
⊢ (𝐷 ∈ 𝑉 → dom (( I ↾ 𝐷) ∖ I ) = dom
((0g‘𝐺)
∖ I )) | 
| 19 |  | resss 6019 | . . . . . . . 8
⊢ ( I
↾ 𝐷) ⊆
I | 
| 20 |  | ssdif0 4366 | . . . . . . . 8
⊢ (( I
↾ 𝐷) ⊆ I ↔
(( I ↾ 𝐷) ∖ I )
= ∅) | 
| 21 | 19, 20 | mpbi 230 | . . . . . . 7
⊢ (( I
↾ 𝐷) ∖ I ) =
∅ | 
| 22 | 21 | dmeqi 5915 | . . . . . 6
⊢ dom (( I
↾ 𝐷) ∖ I ) =
dom ∅ | 
| 23 |  | dm0 5931 | . . . . . 6
⊢ dom
∅ = ∅ | 
| 24 | 22, 23 | eqtri 2765 | . . . . 5
⊢ dom (( I
↾ 𝐷) ∖ I ) =
∅ | 
| 25 |  | 0fi 9082 | . . . . 5
⊢ ∅
∈ Fin | 
| 26 | 24, 25 | eqeltri 2837 | . . . 4
⊢ dom (( I
↾ 𝐷) ∖ I )
∈ Fin | 
| 27 | 18, 26 | eqeltrrdi 2850 | . . 3
⊢ (𝐷 ∈ 𝑉 → dom ((0g‘𝐺) ∖ I ) ∈
Fin) | 
| 28 | 10, 15, 27 | elrabd 3694 | . 2
⊢ (𝐷 ∈ 𝑉 → (0g‘𝐺) ∈ {𝑥 ∈ 𝐵 ∣ dom (𝑥 ∖ I ) ∈ Fin}) | 
| 29 |  | biid 261 | . . 3
⊢ (𝐷 ∈ 𝑉 ↔ 𝐷 ∈ 𝑉) | 
| 30 |  | difeq1 4119 | . . . . . 6
⊢ (𝑥 = 𝑦 → (𝑥 ∖ I ) = (𝑦 ∖ I )) | 
| 31 | 30 | dmeqd 5916 | . . . . 5
⊢ (𝑥 = 𝑦 → dom (𝑥 ∖ I ) = dom (𝑦 ∖ I )) | 
| 32 | 31 | eleq1d 2826 | . . . 4
⊢ (𝑥 = 𝑦 → (dom (𝑥 ∖ I ) ∈ Fin ↔ dom (𝑦 ∖ I ) ∈
Fin)) | 
| 33 | 32 | elrab 3692 | . . 3
⊢ (𝑦 ∈ {𝑥 ∈ 𝐵 ∣ dom (𝑥 ∖ I ) ∈ Fin} ↔ (𝑦 ∈ 𝐵 ∧ dom (𝑦 ∖ I ) ∈ Fin)) | 
| 34 |  | difeq1 4119 | . . . . . 6
⊢ (𝑥 = 𝑧 → (𝑥 ∖ I ) = (𝑧 ∖ I )) | 
| 35 | 34 | dmeqd 5916 | . . . . 5
⊢ (𝑥 = 𝑧 → dom (𝑥 ∖ I ) = dom (𝑧 ∖ I )) | 
| 36 | 35 | eleq1d 2826 | . . . 4
⊢ (𝑥 = 𝑧 → (dom (𝑥 ∖ I ) ∈ Fin ↔ dom (𝑧 ∖ I ) ∈
Fin)) | 
| 37 | 36 | elrab 3692 | . . 3
⊢ (𝑧 ∈ {𝑥 ∈ 𝐵 ∣ dom (𝑥 ∖ I ) ∈ Fin} ↔ (𝑧 ∈ 𝐵 ∧ dom (𝑧 ∖ I ) ∈ Fin)) | 
| 38 |  | difeq1 4119 | . . . . . 6
⊢ (𝑥 = (𝑦(+g‘𝐺)𝑧) → (𝑥 ∖ I ) = ((𝑦(+g‘𝐺)𝑧) ∖ I )) | 
| 39 | 38 | dmeqd 5916 | . . . . 5
⊢ (𝑥 = (𝑦(+g‘𝐺)𝑧) → dom (𝑥 ∖ I ) = dom ((𝑦(+g‘𝐺)𝑧) ∖ I )) | 
| 40 | 39 | eleq1d 2826 | . . . 4
⊢ (𝑥 = (𝑦(+g‘𝐺)𝑧) → (dom (𝑥 ∖ I ) ∈ Fin ↔ dom ((𝑦(+g‘𝐺)𝑧) ∖ I ) ∈ Fin)) | 
| 41 | 12 | 3ad2ant1 1134 | . . . . 5
⊢ ((𝐷 ∈ 𝑉 ∧ (𝑦 ∈ 𝐵 ∧ dom (𝑦 ∖ I ) ∈ Fin) ∧ (𝑧 ∈ 𝐵 ∧ dom (𝑧 ∖ I ) ∈ Fin)) → 𝐺 ∈ Grp) | 
| 42 |  | simp2l 1200 | . . . . 5
⊢ ((𝐷 ∈ 𝑉 ∧ (𝑦 ∈ 𝐵 ∧ dom (𝑦 ∖ I ) ∈ Fin) ∧ (𝑧 ∈ 𝐵 ∧ dom (𝑧 ∖ I ) ∈ Fin)) → 𝑦 ∈ 𝐵) | 
| 43 |  | simp3l 1202 | . . . . 5
⊢ ((𝐷 ∈ 𝑉 ∧ (𝑦 ∈ 𝐵 ∧ dom (𝑦 ∖ I ) ∈ Fin) ∧ (𝑧 ∈ 𝐵 ∧ dom (𝑧 ∖ I ) ∈ Fin)) → 𝑧 ∈ 𝐵) | 
| 44 |  | eqid 2737 | . . . . . 6
⊢
(+g‘𝐺) = (+g‘𝐺) | 
| 45 | 5, 44 | grpcl 18959 | . . . . 5
⊢ ((𝐺 ∈ Grp ∧ 𝑦 ∈ 𝐵 ∧ 𝑧 ∈ 𝐵) → (𝑦(+g‘𝐺)𝑧) ∈ 𝐵) | 
| 46 | 41, 42, 43, 45 | syl3anc 1373 | . . . 4
⊢ ((𝐷 ∈ 𝑉 ∧ (𝑦 ∈ 𝐵 ∧ dom (𝑦 ∖ I ) ∈ Fin) ∧ (𝑧 ∈ 𝐵 ∧ dom (𝑧 ∖ I ) ∈ Fin)) → (𝑦(+g‘𝐺)𝑧) ∈ 𝐵) | 
| 47 | 11, 5, 44 | symgov 19401 | . . . . . . . 8
⊢ ((𝑦 ∈ 𝐵 ∧ 𝑧 ∈ 𝐵) → (𝑦(+g‘𝐺)𝑧) = (𝑦 ∘ 𝑧)) | 
| 48 | 42, 43, 47 | syl2anc 584 | . . . . . . 7
⊢ ((𝐷 ∈ 𝑉 ∧ (𝑦 ∈ 𝐵 ∧ dom (𝑦 ∖ I ) ∈ Fin) ∧ (𝑧 ∈ 𝐵 ∧ dom (𝑧 ∖ I ) ∈ Fin)) → (𝑦(+g‘𝐺)𝑧) = (𝑦 ∘ 𝑧)) | 
| 49 | 48 | difeq1d 4125 | . . . . . 6
⊢ ((𝐷 ∈ 𝑉 ∧ (𝑦 ∈ 𝐵 ∧ dom (𝑦 ∖ I ) ∈ Fin) ∧ (𝑧 ∈ 𝐵 ∧ dom (𝑧 ∖ I ) ∈ Fin)) → ((𝑦(+g‘𝐺)𝑧) ∖ I ) = ((𝑦 ∘ 𝑧) ∖ I )) | 
| 50 | 49 | dmeqd 5916 | . . . . 5
⊢ ((𝐷 ∈ 𝑉 ∧ (𝑦 ∈ 𝐵 ∧ dom (𝑦 ∖ I ) ∈ Fin) ∧ (𝑧 ∈ 𝐵 ∧ dom (𝑧 ∖ I ) ∈ Fin)) → dom ((𝑦(+g‘𝐺)𝑧) ∖ I ) = dom ((𝑦 ∘ 𝑧) ∖ I )) | 
| 51 |  | simp2r 1201 | . . . . . . 7
⊢ ((𝐷 ∈ 𝑉 ∧ (𝑦 ∈ 𝐵 ∧ dom (𝑦 ∖ I ) ∈ Fin) ∧ (𝑧 ∈ 𝐵 ∧ dom (𝑧 ∖ I ) ∈ Fin)) → dom (𝑦 ∖ I ) ∈
Fin) | 
| 52 |  | simp3r 1203 | . . . . . . 7
⊢ ((𝐷 ∈ 𝑉 ∧ (𝑦 ∈ 𝐵 ∧ dom (𝑦 ∖ I ) ∈ Fin) ∧ (𝑧 ∈ 𝐵 ∧ dom (𝑧 ∖ I ) ∈ Fin)) → dom (𝑧 ∖ I ) ∈
Fin) | 
| 53 |  | unfi 9211 | . . . . . . 7
⊢ ((dom
(𝑦 ∖ I ) ∈ Fin
∧ dom (𝑧 ∖ I )
∈ Fin) → (dom (𝑦
∖ I ) ∪ dom (𝑧
∖ I )) ∈ Fin) | 
| 54 | 51, 52, 53 | syl2anc 584 | . . . . . 6
⊢ ((𝐷 ∈ 𝑉 ∧ (𝑦 ∈ 𝐵 ∧ dom (𝑦 ∖ I ) ∈ Fin) ∧ (𝑧 ∈ 𝐵 ∧ dom (𝑧 ∖ I ) ∈ Fin)) → (dom (𝑦 ∖ I ) ∪ dom (𝑧 ∖ I )) ∈
Fin) | 
| 55 |  | mvdco 19463 | . . . . . 6
⊢ dom
((𝑦 ∘ 𝑧) ∖ I ) ⊆ (dom
(𝑦 ∖ I ) ∪ dom
(𝑧 ∖ I
)) | 
| 56 |  | ssfi 9213 | . . . . . 6
⊢ (((dom
(𝑦 ∖ I ) ∪ dom
(𝑧 ∖ I )) ∈ Fin
∧ dom ((𝑦 ∘ 𝑧) ∖ I ) ⊆ (dom
(𝑦 ∖ I ) ∪ dom
(𝑧 ∖ I ))) → dom
((𝑦 ∘ 𝑧) ∖ I ) ∈
Fin) | 
| 57 | 54, 55, 56 | sylancl 586 | . . . . 5
⊢ ((𝐷 ∈ 𝑉 ∧ (𝑦 ∈ 𝐵 ∧ dom (𝑦 ∖ I ) ∈ Fin) ∧ (𝑧 ∈ 𝐵 ∧ dom (𝑧 ∖ I ) ∈ Fin)) → dom ((𝑦 ∘ 𝑧) ∖ I ) ∈ Fin) | 
| 58 | 50, 57 | eqeltrd 2841 | . . . 4
⊢ ((𝐷 ∈ 𝑉 ∧ (𝑦 ∈ 𝐵 ∧ dom (𝑦 ∖ I ) ∈ Fin) ∧ (𝑧 ∈ 𝐵 ∧ dom (𝑧 ∖ I ) ∈ Fin)) → dom ((𝑦(+g‘𝐺)𝑧) ∖ I ) ∈ Fin) | 
| 59 | 40, 46, 58 | elrabd 3694 | . . 3
⊢ ((𝐷 ∈ 𝑉 ∧ (𝑦 ∈ 𝐵 ∧ dom (𝑦 ∖ I ) ∈ Fin) ∧ (𝑧 ∈ 𝐵 ∧ dom (𝑧 ∖ I ) ∈ Fin)) → (𝑦(+g‘𝐺)𝑧) ∈ {𝑥 ∈ 𝐵 ∣ dom (𝑥 ∖ I ) ∈ Fin}) | 
| 60 | 29, 33, 37, 59 | syl3anb 1162 | . 2
⊢ ((𝐷 ∈ 𝑉 ∧ 𝑦 ∈ {𝑥 ∈ 𝐵 ∣ dom (𝑥 ∖ I ) ∈ Fin} ∧ 𝑧 ∈ {𝑥 ∈ 𝐵 ∣ dom (𝑥 ∖ I ) ∈ Fin}) → (𝑦(+g‘𝐺)𝑧) ∈ {𝑥 ∈ 𝐵 ∣ dom (𝑥 ∖ I ) ∈ Fin}) | 
| 61 |  | difeq1 4119 | . . . . . 6
⊢ (𝑥 = ((invg‘𝐺)‘𝑦) → (𝑥 ∖ I ) = (((invg‘𝐺)‘𝑦) ∖ I )) | 
| 62 | 61 | dmeqd 5916 | . . . . 5
⊢ (𝑥 = ((invg‘𝐺)‘𝑦) → dom (𝑥 ∖ I ) = dom
(((invg‘𝐺)‘𝑦) ∖ I )) | 
| 63 | 62 | eleq1d 2826 | . . . 4
⊢ (𝑥 = ((invg‘𝐺)‘𝑦) → (dom (𝑥 ∖ I ) ∈ Fin ↔ dom
(((invg‘𝐺)‘𝑦) ∖ I ) ∈ Fin)) | 
| 64 |  | simprl 771 | . . . . 5
⊢ ((𝐷 ∈ 𝑉 ∧ (𝑦 ∈ 𝐵 ∧ dom (𝑦 ∖ I ) ∈ Fin)) → 𝑦 ∈ 𝐵) | 
| 65 |  | eqid 2737 | . . . . . 6
⊢
(invg‘𝐺) = (invg‘𝐺) | 
| 66 | 5, 65 | grpinvcl 19005 | . . . . 5
⊢ ((𝐺 ∈ Grp ∧ 𝑦 ∈ 𝐵) → ((invg‘𝐺)‘𝑦) ∈ 𝐵) | 
| 67 | 12, 64, 66 | syl2an2r 685 | . . . 4
⊢ ((𝐷 ∈ 𝑉 ∧ (𝑦 ∈ 𝐵 ∧ dom (𝑦 ∖ I ) ∈ Fin)) →
((invg‘𝐺)‘𝑦) ∈ 𝐵) | 
| 68 | 11, 5, 65 | symginv 19420 | . . . . . . . . 9
⊢ (𝑦 ∈ 𝐵 → ((invg‘𝐺)‘𝑦) = ◡𝑦) | 
| 69 | 68 | ad2antrl 728 | . . . . . . . 8
⊢ ((𝐷 ∈ 𝑉 ∧ (𝑦 ∈ 𝐵 ∧ dom (𝑦 ∖ I ) ∈ Fin)) →
((invg‘𝐺)‘𝑦) = ◡𝑦) | 
| 70 | 69 | difeq1d 4125 | . . . . . . 7
⊢ ((𝐷 ∈ 𝑉 ∧ (𝑦 ∈ 𝐵 ∧ dom (𝑦 ∖ I ) ∈ Fin)) →
(((invg‘𝐺)‘𝑦) ∖ I ) = (◡𝑦 ∖ I )) | 
| 71 | 70 | dmeqd 5916 | . . . . . 6
⊢ ((𝐷 ∈ 𝑉 ∧ (𝑦 ∈ 𝐵 ∧ dom (𝑦 ∖ I ) ∈ Fin)) → dom
(((invg‘𝐺)‘𝑦) ∖ I ) = dom (◡𝑦 ∖ I )) | 
| 72 | 11, 5 | symgbasf1o 19392 | . . . . . . . 8
⊢ (𝑦 ∈ 𝐵 → 𝑦:𝐷–1-1-onto→𝐷) | 
| 73 | 72 | ad2antrl 728 | . . . . . . 7
⊢ ((𝐷 ∈ 𝑉 ∧ (𝑦 ∈ 𝐵 ∧ dom (𝑦 ∖ I ) ∈ Fin)) → 𝑦:𝐷–1-1-onto→𝐷) | 
| 74 |  | f1omvdcnv 19462 | . . . . . . 7
⊢ (𝑦:𝐷–1-1-onto→𝐷 → dom (◡𝑦 ∖ I ) = dom (𝑦 ∖ I )) | 
| 75 | 73, 74 | syl 17 | . . . . . 6
⊢ ((𝐷 ∈ 𝑉 ∧ (𝑦 ∈ 𝐵 ∧ dom (𝑦 ∖ I ) ∈ Fin)) → dom (◡𝑦 ∖ I ) = dom (𝑦 ∖ I )) | 
| 76 | 71, 75 | eqtrd 2777 | . . . . 5
⊢ ((𝐷 ∈ 𝑉 ∧ (𝑦 ∈ 𝐵 ∧ dom (𝑦 ∖ I ) ∈ Fin)) → dom
(((invg‘𝐺)‘𝑦) ∖ I ) = dom (𝑦 ∖ I )) | 
| 77 |  | simprr 773 | . . . . 5
⊢ ((𝐷 ∈ 𝑉 ∧ (𝑦 ∈ 𝐵 ∧ dom (𝑦 ∖ I ) ∈ Fin)) → dom (𝑦 ∖ I ) ∈
Fin) | 
| 78 | 76, 77 | eqeltrd 2841 | . . . 4
⊢ ((𝐷 ∈ 𝑉 ∧ (𝑦 ∈ 𝐵 ∧ dom (𝑦 ∖ I ) ∈ Fin)) → dom
(((invg‘𝐺)‘𝑦) ∖ I ) ∈ Fin) | 
| 79 | 63, 67, 78 | elrabd 3694 | . . 3
⊢ ((𝐷 ∈ 𝑉 ∧ (𝑦 ∈ 𝐵 ∧ dom (𝑦 ∖ I ) ∈ Fin)) →
((invg‘𝐺)‘𝑦) ∈ {𝑥 ∈ 𝐵 ∣ dom (𝑥 ∖ I ) ∈ Fin}) | 
| 80 | 33, 79 | sylan2b 594 | . 2
⊢ ((𝐷 ∈ 𝑉 ∧ 𝑦 ∈ {𝑥 ∈ 𝐵 ∣ dom (𝑥 ∖ I ) ∈ Fin}) →
((invg‘𝐺)‘𝑦) ∈ {𝑥 ∈ 𝐵 ∣ dom (𝑥 ∖ I ) ∈ Fin}) | 
| 81 | 1, 2, 3, 7, 28, 60, 80, 12 | issubgrpd2 19160 | 1
⊢ (𝐷 ∈ 𝑉 → {𝑥 ∈ 𝐵 ∣ dom (𝑥 ∖ I ) ∈ Fin} ∈
(SubGrp‘𝐺)) |