Metamath Proof Explorer


Theorem nsgmgclem

Description: Lemma for nsgmgc . (Contributed by Thierry Arnoux, 27-Jul-2024)

Ref Expression
Hypotheses nsgmgclem.b 𝐵 = ( Base ‘ 𝐺 )
nsgmgclem.q 𝑄 = ( 𝐺 /s ( 𝐺 ~QG 𝑁 ) )
nsgmgclem.p = ( LSSum ‘ 𝐺 )
nsgmgclem.n ( 𝜑𝑁 ∈ ( NrmSGrp ‘ 𝐺 ) )
nsgmgclem.f ( 𝜑𝐹 ∈ ( SubGrp ‘ 𝑄 ) )
Assertion nsgmgclem ( 𝜑 → { 𝑎𝐵 ∣ ( { 𝑎 } 𝑁 ) ∈ 𝐹 } ∈ ( SubGrp ‘ 𝐺 ) )

Proof

Step Hyp Ref Expression
1 nsgmgclem.b 𝐵 = ( Base ‘ 𝐺 )
2 nsgmgclem.q 𝑄 = ( 𝐺 /s ( 𝐺 ~QG 𝑁 ) )
3 nsgmgclem.p = ( LSSum ‘ 𝐺 )
4 nsgmgclem.n ( 𝜑𝑁 ∈ ( NrmSGrp ‘ 𝐺 ) )
5 nsgmgclem.f ( 𝜑𝐹 ∈ ( SubGrp ‘ 𝑄 ) )
6 eqidd ( 𝜑 → ( 𝐺s { 𝑎𝐵 ∣ ( { 𝑎 } 𝑁 ) ∈ 𝐹 } ) = ( 𝐺s { 𝑎𝐵 ∣ ( { 𝑎 } 𝑁 ) ∈ 𝐹 } ) )
7 eqidd ( 𝜑 → ( 0g𝐺 ) = ( 0g𝐺 ) )
8 eqidd ( 𝜑 → ( +g𝐺 ) = ( +g𝐺 ) )
9 ssrab2 { 𝑎𝐵 ∣ ( { 𝑎 } 𝑁 ) ∈ 𝐹 } ⊆ 𝐵
10 9 a1i ( 𝜑 → { 𝑎𝐵 ∣ ( { 𝑎 } 𝑁 ) ∈ 𝐹 } ⊆ 𝐵 )
11 10 1 sseqtrdi ( 𝜑 → { 𝑎𝐵 ∣ ( { 𝑎 } 𝑁 ) ∈ 𝐹 } ⊆ ( Base ‘ 𝐺 ) )
12 sneq ( 𝑎 = ( 0g𝐺 ) → { 𝑎 } = { ( 0g𝐺 ) } )
13 12 oveq1d ( 𝑎 = ( 0g𝐺 ) → ( { 𝑎 } 𝑁 ) = ( { ( 0g𝐺 ) } 𝑁 ) )
14 13 eleq1d ( 𝑎 = ( 0g𝐺 ) → ( ( { 𝑎 } 𝑁 ) ∈ 𝐹 ↔ ( { ( 0g𝐺 ) } 𝑁 ) ∈ 𝐹 ) )
15 nsgsubg ( 𝑁 ∈ ( NrmSGrp ‘ 𝐺 ) → 𝑁 ∈ ( SubGrp ‘ 𝐺 ) )
16 4 15 syl ( 𝜑𝑁 ∈ ( SubGrp ‘ 𝐺 ) )
17 subgrcl ( 𝑁 ∈ ( SubGrp ‘ 𝐺 ) → 𝐺 ∈ Grp )
18 16 17 syl ( 𝜑𝐺 ∈ Grp )
19 eqid ( 0g𝐺 ) = ( 0g𝐺 )
20 1 19 grpidcl ( 𝐺 ∈ Grp → ( 0g𝐺 ) ∈ 𝐵 )
21 18 20 syl ( 𝜑 → ( 0g𝐺 ) ∈ 𝐵 )
22 19 3 lsm02 ( 𝑁 ∈ ( SubGrp ‘ 𝐺 ) → ( { ( 0g𝐺 ) } 𝑁 ) = 𝑁 )
23 16 22 syl ( 𝜑 → ( { ( 0g𝐺 ) } 𝑁 ) = 𝑁 )
24 2 nsgqus0 ( ( 𝑁 ∈ ( NrmSGrp ‘ 𝐺 ) ∧ 𝐹 ∈ ( SubGrp ‘ 𝑄 ) ) → 𝑁𝐹 )
25 4 5 24 syl2anc ( 𝜑𝑁𝐹 )
26 23 25 eqeltrd ( 𝜑 → ( { ( 0g𝐺 ) } 𝑁 ) ∈ 𝐹 )
27 14 21 26 elrabd ( 𝜑 → ( 0g𝐺 ) ∈ { 𝑎𝐵 ∣ ( { 𝑎 } 𝑁 ) ∈ 𝐹 } )
28 sneq ( 𝑎 = ( 𝑥 ( +g𝐺 ) 𝑦 ) → { 𝑎 } = { ( 𝑥 ( +g𝐺 ) 𝑦 ) } )
29 28 oveq1d ( 𝑎 = ( 𝑥 ( +g𝐺 ) 𝑦 ) → ( { 𝑎 } 𝑁 ) = ( { ( 𝑥 ( +g𝐺 ) 𝑦 ) } 𝑁 ) )
30 29 eleq1d ( 𝑎 = ( 𝑥 ( +g𝐺 ) 𝑦 ) → ( ( { 𝑎 } 𝑁 ) ∈ 𝐹 ↔ ( { ( 𝑥 ( +g𝐺 ) 𝑦 ) } 𝑁 ) ∈ 𝐹 ) )
31 18 ad2antrr ( ( ( 𝜑𝑥 ∈ { 𝑎𝐵 ∣ ( { 𝑎 } 𝑁 ) ∈ 𝐹 } ) ∧ 𝑦 ∈ { 𝑎𝐵 ∣ ( { 𝑎 } 𝑁 ) ∈ 𝐹 } ) → 𝐺 ∈ Grp )
32 elrabi ( 𝑥 ∈ { 𝑎𝐵 ∣ ( { 𝑎 } 𝑁 ) ∈ 𝐹 } → 𝑥𝐵 )
33 32 ad2antlr ( ( ( 𝜑𝑥 ∈ { 𝑎𝐵 ∣ ( { 𝑎 } 𝑁 ) ∈ 𝐹 } ) ∧ 𝑦 ∈ { 𝑎𝐵 ∣ ( { 𝑎 } 𝑁 ) ∈ 𝐹 } ) → 𝑥𝐵 )
34 elrabi ( 𝑦 ∈ { 𝑎𝐵 ∣ ( { 𝑎 } 𝑁 ) ∈ 𝐹 } → 𝑦𝐵 )
35 34 adantl ( ( ( 𝜑𝑥 ∈ { 𝑎𝐵 ∣ ( { 𝑎 } 𝑁 ) ∈ 𝐹 } ) ∧ 𝑦 ∈ { 𝑎𝐵 ∣ ( { 𝑎 } 𝑁 ) ∈ 𝐹 } ) → 𝑦𝐵 )
36 eqid ( +g𝐺 ) = ( +g𝐺 )
37 1 36 grpcl ( ( 𝐺 ∈ Grp ∧ 𝑥𝐵𝑦𝐵 ) → ( 𝑥 ( +g𝐺 ) 𝑦 ) ∈ 𝐵 )
38 31 33 35 37 syl3anc ( ( ( 𝜑𝑥 ∈ { 𝑎𝐵 ∣ ( { 𝑎 } 𝑁 ) ∈ 𝐹 } ) ∧ 𝑦 ∈ { 𝑎𝐵 ∣ ( { 𝑎 } 𝑁 ) ∈ 𝐹 } ) → ( 𝑥 ( +g𝐺 ) 𝑦 ) ∈ 𝐵 )
39 16 ad2antrr ( ( ( 𝜑𝑥 ∈ { 𝑎𝐵 ∣ ( { 𝑎 } 𝑁 ) ∈ 𝐹 } ) ∧ 𝑦 ∈ { 𝑎𝐵 ∣ ( { 𝑎 } 𝑁 ) ∈ 𝐹 } ) → 𝑁 ∈ ( SubGrp ‘ 𝐺 ) )
40 1 3 39 38 quslsm ( ( ( 𝜑𝑥 ∈ { 𝑎𝐵 ∣ ( { 𝑎 } 𝑁 ) ∈ 𝐹 } ) ∧ 𝑦 ∈ { 𝑎𝐵 ∣ ( { 𝑎 } 𝑁 ) ∈ 𝐹 } ) → [ ( 𝑥 ( +g𝐺 ) 𝑦 ) ] ( 𝐺 ~QG 𝑁 ) = ( { ( 𝑥 ( +g𝐺 ) 𝑦 ) } 𝑁 ) )
41 4 ad2antrr ( ( ( 𝜑𝑥 ∈ { 𝑎𝐵 ∣ ( { 𝑎 } 𝑁 ) ∈ 𝐹 } ) ∧ 𝑦 ∈ { 𝑎𝐵 ∣ ( { 𝑎 } 𝑁 ) ∈ 𝐹 } ) → 𝑁 ∈ ( NrmSGrp ‘ 𝐺 ) )
42 eqid ( +g𝑄 ) = ( +g𝑄 )
43 2 1 36 42 qusadd ( ( 𝑁 ∈ ( NrmSGrp ‘ 𝐺 ) ∧ 𝑥𝐵𝑦𝐵 ) → ( [ 𝑥 ] ( 𝐺 ~QG 𝑁 ) ( +g𝑄 ) [ 𝑦 ] ( 𝐺 ~QG 𝑁 ) ) = [ ( 𝑥 ( +g𝐺 ) 𝑦 ) ] ( 𝐺 ~QG 𝑁 ) )
44 41 33 35 43 syl3anc ( ( ( 𝜑𝑥 ∈ { 𝑎𝐵 ∣ ( { 𝑎 } 𝑁 ) ∈ 𝐹 } ) ∧ 𝑦 ∈ { 𝑎𝐵 ∣ ( { 𝑎 } 𝑁 ) ∈ 𝐹 } ) → ( [ 𝑥 ] ( 𝐺 ~QG 𝑁 ) ( +g𝑄 ) [ 𝑦 ] ( 𝐺 ~QG 𝑁 ) ) = [ ( 𝑥 ( +g𝐺 ) 𝑦 ) ] ( 𝐺 ~QG 𝑁 ) )
45 5 ad2antrr ( ( ( 𝜑𝑥 ∈ { 𝑎𝐵 ∣ ( { 𝑎 } 𝑁 ) ∈ 𝐹 } ) ∧ 𝑦 ∈ { 𝑎𝐵 ∣ ( { 𝑎 } 𝑁 ) ∈ 𝐹 } ) → 𝐹 ∈ ( SubGrp ‘ 𝑄 ) )
46 1 3 39 33 quslsm ( ( ( 𝜑𝑥 ∈ { 𝑎𝐵 ∣ ( { 𝑎 } 𝑁 ) ∈ 𝐹 } ) ∧ 𝑦 ∈ { 𝑎𝐵 ∣ ( { 𝑎 } 𝑁 ) ∈ 𝐹 } ) → [ 𝑥 ] ( 𝐺 ~QG 𝑁 ) = ( { 𝑥 } 𝑁 ) )
47 sneq ( 𝑎 = 𝑥 → { 𝑎 } = { 𝑥 } )
48 47 oveq1d ( 𝑎 = 𝑥 → ( { 𝑎 } 𝑁 ) = ( { 𝑥 } 𝑁 ) )
49 48 eleq1d ( 𝑎 = 𝑥 → ( ( { 𝑎 } 𝑁 ) ∈ 𝐹 ↔ ( { 𝑥 } 𝑁 ) ∈ 𝐹 ) )
50 49 elrab ( 𝑥 ∈ { 𝑎𝐵 ∣ ( { 𝑎 } 𝑁 ) ∈ 𝐹 } ↔ ( 𝑥𝐵 ∧ ( { 𝑥 } 𝑁 ) ∈ 𝐹 ) )
51 50 simprbi ( 𝑥 ∈ { 𝑎𝐵 ∣ ( { 𝑎 } 𝑁 ) ∈ 𝐹 } → ( { 𝑥 } 𝑁 ) ∈ 𝐹 )
52 51 ad2antlr ( ( ( 𝜑𝑥 ∈ { 𝑎𝐵 ∣ ( { 𝑎 } 𝑁 ) ∈ 𝐹 } ) ∧ 𝑦 ∈ { 𝑎𝐵 ∣ ( { 𝑎 } 𝑁 ) ∈ 𝐹 } ) → ( { 𝑥 } 𝑁 ) ∈ 𝐹 )
53 46 52 eqeltrd ( ( ( 𝜑𝑥 ∈ { 𝑎𝐵 ∣ ( { 𝑎 } 𝑁 ) ∈ 𝐹 } ) ∧ 𝑦 ∈ { 𝑎𝐵 ∣ ( { 𝑎 } 𝑁 ) ∈ 𝐹 } ) → [ 𝑥 ] ( 𝐺 ~QG 𝑁 ) ∈ 𝐹 )
54 1 3 39 35 quslsm ( ( ( 𝜑𝑥 ∈ { 𝑎𝐵 ∣ ( { 𝑎 } 𝑁 ) ∈ 𝐹 } ) ∧ 𝑦 ∈ { 𝑎𝐵 ∣ ( { 𝑎 } 𝑁 ) ∈ 𝐹 } ) → [ 𝑦 ] ( 𝐺 ~QG 𝑁 ) = ( { 𝑦 } 𝑁 ) )
55 sneq ( 𝑎 = 𝑦 → { 𝑎 } = { 𝑦 } )
56 55 oveq1d ( 𝑎 = 𝑦 → ( { 𝑎 } 𝑁 ) = ( { 𝑦 } 𝑁 ) )
57 56 eleq1d ( 𝑎 = 𝑦 → ( ( { 𝑎 } 𝑁 ) ∈ 𝐹 ↔ ( { 𝑦 } 𝑁 ) ∈ 𝐹 ) )
58 57 elrab ( 𝑦 ∈ { 𝑎𝐵 ∣ ( { 𝑎 } 𝑁 ) ∈ 𝐹 } ↔ ( 𝑦𝐵 ∧ ( { 𝑦 } 𝑁 ) ∈ 𝐹 ) )
59 58 simprbi ( 𝑦 ∈ { 𝑎𝐵 ∣ ( { 𝑎 } 𝑁 ) ∈ 𝐹 } → ( { 𝑦 } 𝑁 ) ∈ 𝐹 )
60 59 adantl ( ( ( 𝜑𝑥 ∈ { 𝑎𝐵 ∣ ( { 𝑎 } 𝑁 ) ∈ 𝐹 } ) ∧ 𝑦 ∈ { 𝑎𝐵 ∣ ( { 𝑎 } 𝑁 ) ∈ 𝐹 } ) → ( { 𝑦 } 𝑁 ) ∈ 𝐹 )
61 54 60 eqeltrd ( ( ( 𝜑𝑥 ∈ { 𝑎𝐵 ∣ ( { 𝑎 } 𝑁 ) ∈ 𝐹 } ) ∧ 𝑦 ∈ { 𝑎𝐵 ∣ ( { 𝑎 } 𝑁 ) ∈ 𝐹 } ) → [ 𝑦 ] ( 𝐺 ~QG 𝑁 ) ∈ 𝐹 )
62 42 subgcl ( ( 𝐹 ∈ ( SubGrp ‘ 𝑄 ) ∧ [ 𝑥 ] ( 𝐺 ~QG 𝑁 ) ∈ 𝐹 ∧ [ 𝑦 ] ( 𝐺 ~QG 𝑁 ) ∈ 𝐹 ) → ( [ 𝑥 ] ( 𝐺 ~QG 𝑁 ) ( +g𝑄 ) [ 𝑦 ] ( 𝐺 ~QG 𝑁 ) ) ∈ 𝐹 )
63 45 53 61 62 syl3anc ( ( ( 𝜑𝑥 ∈ { 𝑎𝐵 ∣ ( { 𝑎 } 𝑁 ) ∈ 𝐹 } ) ∧ 𝑦 ∈ { 𝑎𝐵 ∣ ( { 𝑎 } 𝑁 ) ∈ 𝐹 } ) → ( [ 𝑥 ] ( 𝐺 ~QG 𝑁 ) ( +g𝑄 ) [ 𝑦 ] ( 𝐺 ~QG 𝑁 ) ) ∈ 𝐹 )
64 44 63 eqeltrrd ( ( ( 𝜑𝑥 ∈ { 𝑎𝐵 ∣ ( { 𝑎 } 𝑁 ) ∈ 𝐹 } ) ∧ 𝑦 ∈ { 𝑎𝐵 ∣ ( { 𝑎 } 𝑁 ) ∈ 𝐹 } ) → [ ( 𝑥 ( +g𝐺 ) 𝑦 ) ] ( 𝐺 ~QG 𝑁 ) ∈ 𝐹 )
65 40 64 eqeltrrd ( ( ( 𝜑𝑥 ∈ { 𝑎𝐵 ∣ ( { 𝑎 } 𝑁 ) ∈ 𝐹 } ) ∧ 𝑦 ∈ { 𝑎𝐵 ∣ ( { 𝑎 } 𝑁 ) ∈ 𝐹 } ) → ( { ( 𝑥 ( +g𝐺 ) 𝑦 ) } 𝑁 ) ∈ 𝐹 )
66 30 38 65 elrabd ( ( ( 𝜑𝑥 ∈ { 𝑎𝐵 ∣ ( { 𝑎 } 𝑁 ) ∈ 𝐹 } ) ∧ 𝑦 ∈ { 𝑎𝐵 ∣ ( { 𝑎 } 𝑁 ) ∈ 𝐹 } ) → ( 𝑥 ( +g𝐺 ) 𝑦 ) ∈ { 𝑎𝐵 ∣ ( { 𝑎 } 𝑁 ) ∈ 𝐹 } )
67 66 3impa ( ( 𝜑𝑥 ∈ { 𝑎𝐵 ∣ ( { 𝑎 } 𝑁 ) ∈ 𝐹 } ∧ 𝑦 ∈ { 𝑎𝐵 ∣ ( { 𝑎 } 𝑁 ) ∈ 𝐹 } ) → ( 𝑥 ( +g𝐺 ) 𝑦 ) ∈ { 𝑎𝐵 ∣ ( { 𝑎 } 𝑁 ) ∈ 𝐹 } )
68 sneq ( 𝑎 = ( ( invg𝐺 ) ‘ 𝑥 ) → { 𝑎 } = { ( ( invg𝐺 ) ‘ 𝑥 ) } )
69 68 oveq1d ( 𝑎 = ( ( invg𝐺 ) ‘ 𝑥 ) → ( { 𝑎 } 𝑁 ) = ( { ( ( invg𝐺 ) ‘ 𝑥 ) } 𝑁 ) )
70 69 eleq1d ( 𝑎 = ( ( invg𝐺 ) ‘ 𝑥 ) → ( ( { 𝑎 } 𝑁 ) ∈ 𝐹 ↔ ( { ( ( invg𝐺 ) ‘ 𝑥 ) } 𝑁 ) ∈ 𝐹 ) )
71 eqid ( invg𝐺 ) = ( invg𝐺 )
72 1 71 grpinvcl ( ( 𝐺 ∈ Grp ∧ 𝑥𝐵 ) → ( ( invg𝐺 ) ‘ 𝑥 ) ∈ 𝐵 )
73 18 72 sylan ( ( 𝜑𝑥𝐵 ) → ( ( invg𝐺 ) ‘ 𝑥 ) ∈ 𝐵 )
74 73 adantr ( ( ( 𝜑𝑥𝐵 ) ∧ ( { 𝑥 } 𝑁 ) ∈ 𝐹 ) → ( ( invg𝐺 ) ‘ 𝑥 ) ∈ 𝐵 )
75 eqid ( invg𝑄 ) = ( invg𝑄 )
76 2 1 71 75 qusinv ( ( 𝑁 ∈ ( NrmSGrp ‘ 𝐺 ) ∧ 𝑥𝐵 ) → ( ( invg𝑄 ) ‘ [ 𝑥 ] ( 𝐺 ~QG 𝑁 ) ) = [ ( ( invg𝐺 ) ‘ 𝑥 ) ] ( 𝐺 ~QG 𝑁 ) )
77 4 76 sylan ( ( 𝜑𝑥𝐵 ) → ( ( invg𝑄 ) ‘ [ 𝑥 ] ( 𝐺 ~QG 𝑁 ) ) = [ ( ( invg𝐺 ) ‘ 𝑥 ) ] ( 𝐺 ~QG 𝑁 ) )
78 16 adantr ( ( 𝜑𝑥𝐵 ) → 𝑁 ∈ ( SubGrp ‘ 𝐺 ) )
79 simpr ( ( 𝜑𝑥𝐵 ) → 𝑥𝐵 )
80 1 3 78 79 quslsm ( ( 𝜑𝑥𝐵 ) → [ 𝑥 ] ( 𝐺 ~QG 𝑁 ) = ( { 𝑥 } 𝑁 ) )
81 80 fveq2d ( ( 𝜑𝑥𝐵 ) → ( ( invg𝑄 ) ‘ [ 𝑥 ] ( 𝐺 ~QG 𝑁 ) ) = ( ( invg𝑄 ) ‘ ( { 𝑥 } 𝑁 ) ) )
82 1 3 78 73 quslsm ( ( 𝜑𝑥𝐵 ) → [ ( ( invg𝐺 ) ‘ 𝑥 ) ] ( 𝐺 ~QG 𝑁 ) = ( { ( ( invg𝐺 ) ‘ 𝑥 ) } 𝑁 ) )
83 77 81 82 3eqtr3d ( ( 𝜑𝑥𝐵 ) → ( ( invg𝑄 ) ‘ ( { 𝑥 } 𝑁 ) ) = ( { ( ( invg𝐺 ) ‘ 𝑥 ) } 𝑁 ) )
84 83 adantr ( ( ( 𝜑𝑥𝐵 ) ∧ ( { 𝑥 } 𝑁 ) ∈ 𝐹 ) → ( ( invg𝑄 ) ‘ ( { 𝑥 } 𝑁 ) ) = ( { ( ( invg𝐺 ) ‘ 𝑥 ) } 𝑁 ) )
85 5 ad2antrr ( ( ( 𝜑𝑥𝐵 ) ∧ ( { 𝑥 } 𝑁 ) ∈ 𝐹 ) → 𝐹 ∈ ( SubGrp ‘ 𝑄 ) )
86 simpr ( ( ( 𝜑𝑥𝐵 ) ∧ ( { 𝑥 } 𝑁 ) ∈ 𝐹 ) → ( { 𝑥 } 𝑁 ) ∈ 𝐹 )
87 75 subginvcl ( ( 𝐹 ∈ ( SubGrp ‘ 𝑄 ) ∧ ( { 𝑥 } 𝑁 ) ∈ 𝐹 ) → ( ( invg𝑄 ) ‘ ( { 𝑥 } 𝑁 ) ) ∈ 𝐹 )
88 85 86 87 syl2anc ( ( ( 𝜑𝑥𝐵 ) ∧ ( { 𝑥 } 𝑁 ) ∈ 𝐹 ) → ( ( invg𝑄 ) ‘ ( { 𝑥 } 𝑁 ) ) ∈ 𝐹 )
89 84 88 eqeltrrd ( ( ( 𝜑𝑥𝐵 ) ∧ ( { 𝑥 } 𝑁 ) ∈ 𝐹 ) → ( { ( ( invg𝐺 ) ‘ 𝑥 ) } 𝑁 ) ∈ 𝐹 )
90 70 74 89 elrabd ( ( ( 𝜑𝑥𝐵 ) ∧ ( { 𝑥 } 𝑁 ) ∈ 𝐹 ) → ( ( invg𝐺 ) ‘ 𝑥 ) ∈ { 𝑎𝐵 ∣ ( { 𝑎 } 𝑁 ) ∈ 𝐹 } )
91 90 anasss ( ( 𝜑 ∧ ( 𝑥𝐵 ∧ ( { 𝑥 } 𝑁 ) ∈ 𝐹 ) ) → ( ( invg𝐺 ) ‘ 𝑥 ) ∈ { 𝑎𝐵 ∣ ( { 𝑎 } 𝑁 ) ∈ 𝐹 } )
92 50 91 sylan2b ( ( 𝜑𝑥 ∈ { 𝑎𝐵 ∣ ( { 𝑎 } 𝑁 ) ∈ 𝐹 } ) → ( ( invg𝐺 ) ‘ 𝑥 ) ∈ { 𝑎𝐵 ∣ ( { 𝑎 } 𝑁 ) ∈ 𝐹 } )
93 6 7 8 11 27 67 92 18 issubgrpd2 ( 𝜑 → { 𝑎𝐵 ∣ ( { 𝑎 } 𝑁 ) ∈ 𝐹 } ∈ ( SubGrp ‘ 𝐺 ) )