Metamath Proof Explorer


Theorem dprdz

Description: A family consisting entirely of trivial groups is an internal direct product, the product of which is the trivial subgroup. (Contributed by Mario Carneiro, 25-Apr-2016)

Ref Expression
Hypothesis dprd0.0 0 = ( 0g𝐺 )
Assertion dprdz ( ( 𝐺 ∈ Grp ∧ 𝐼𝑉 ) → ( 𝐺 dom DProd ( 𝑥𝐼 ↦ { 0 } ) ∧ ( 𝐺 DProd ( 𝑥𝐼 ↦ { 0 } ) ) = { 0 } ) )

Proof

Step Hyp Ref Expression
1 dprd0.0 0 = ( 0g𝐺 )
2 eqid ( Cntz ‘ 𝐺 ) = ( Cntz ‘ 𝐺 )
3 eqid ( mrCls ‘ ( SubGrp ‘ 𝐺 ) ) = ( mrCls ‘ ( SubGrp ‘ 𝐺 ) )
4 simpl ( ( 𝐺 ∈ Grp ∧ 𝐼𝑉 ) → 𝐺 ∈ Grp )
5 simpr ( ( 𝐺 ∈ Grp ∧ 𝐼𝑉 ) → 𝐼𝑉 )
6 1 0subg ( 𝐺 ∈ Grp → { 0 } ∈ ( SubGrp ‘ 𝐺 ) )
7 6 ad2antrr ( ( ( 𝐺 ∈ Grp ∧ 𝐼𝑉 ) ∧ 𝑥𝐼 ) → { 0 } ∈ ( SubGrp ‘ 𝐺 ) )
8 7 fmpttd ( ( 𝐺 ∈ Grp ∧ 𝐼𝑉 ) → ( 𝑥𝐼 ↦ { 0 } ) : 𝐼 ⟶ ( SubGrp ‘ 𝐺 ) )
9 eqid ( Base ‘ 𝐺 ) = ( Base ‘ 𝐺 )
10 9 1 grpidcl ( 𝐺 ∈ Grp → 0 ∈ ( Base ‘ 𝐺 ) )
11 10 adantr ( ( 𝐺 ∈ Grp ∧ 𝐼𝑉 ) → 0 ∈ ( Base ‘ 𝐺 ) )
12 11 snssd ( ( 𝐺 ∈ Grp ∧ 𝐼𝑉 ) → { 0 } ⊆ ( Base ‘ 𝐺 ) )
13 9 2 cntzsubg ( ( 𝐺 ∈ Grp ∧ { 0 } ⊆ ( Base ‘ 𝐺 ) ) → ( ( Cntz ‘ 𝐺 ) ‘ { 0 } ) ∈ ( SubGrp ‘ 𝐺 ) )
14 12 13 syldan ( ( 𝐺 ∈ Grp ∧ 𝐼𝑉 ) → ( ( Cntz ‘ 𝐺 ) ‘ { 0 } ) ∈ ( SubGrp ‘ 𝐺 ) )
15 1 subg0cl ( ( ( Cntz ‘ 𝐺 ) ‘ { 0 } ) ∈ ( SubGrp ‘ 𝐺 ) → 0 ∈ ( ( Cntz ‘ 𝐺 ) ‘ { 0 } ) )
16 14 15 syl ( ( 𝐺 ∈ Grp ∧ 𝐼𝑉 ) → 0 ∈ ( ( Cntz ‘ 𝐺 ) ‘ { 0 } ) )
17 16 snssd ( ( 𝐺 ∈ Grp ∧ 𝐼𝑉 ) → { 0 } ⊆ ( ( Cntz ‘ 𝐺 ) ‘ { 0 } ) )
18 17 adantr ( ( ( 𝐺 ∈ Grp ∧ 𝐼𝑉 ) ∧ ( 𝑦𝐼𝑧𝐼𝑦𝑧 ) ) → { 0 } ⊆ ( ( Cntz ‘ 𝐺 ) ‘ { 0 } ) )
19 simpr1 ( ( ( 𝐺 ∈ Grp ∧ 𝐼𝑉 ) ∧ ( 𝑦𝐼𝑧𝐼𝑦𝑧 ) ) → 𝑦𝐼 )
20 eqidd ( 𝑥 = 𝑦 → { 0 } = { 0 } )
21 eqid ( 𝑥𝐼 ↦ { 0 } ) = ( 𝑥𝐼 ↦ { 0 } )
22 snex { 0 } ∈ V
23 20 21 22 fvmpt3i ( 𝑦𝐼 → ( ( 𝑥𝐼 ↦ { 0 } ) ‘ 𝑦 ) = { 0 } )
24 19 23 syl ( ( ( 𝐺 ∈ Grp ∧ 𝐼𝑉 ) ∧ ( 𝑦𝐼𝑧𝐼𝑦𝑧 ) ) → ( ( 𝑥𝐼 ↦ { 0 } ) ‘ 𝑦 ) = { 0 } )
25 simpr2 ( ( ( 𝐺 ∈ Grp ∧ 𝐼𝑉 ) ∧ ( 𝑦𝐼𝑧𝐼𝑦𝑧 ) ) → 𝑧𝐼 )
26 eqidd ( 𝑥 = 𝑧 → { 0 } = { 0 } )
27 26 21 22 fvmpt3i ( 𝑧𝐼 → ( ( 𝑥𝐼 ↦ { 0 } ) ‘ 𝑧 ) = { 0 } )
28 25 27 syl ( ( ( 𝐺 ∈ Grp ∧ 𝐼𝑉 ) ∧ ( 𝑦𝐼𝑧𝐼𝑦𝑧 ) ) → ( ( 𝑥𝐼 ↦ { 0 } ) ‘ 𝑧 ) = { 0 } )
29 28 fveq2d ( ( ( 𝐺 ∈ Grp ∧ 𝐼𝑉 ) ∧ ( 𝑦𝐼𝑧𝐼𝑦𝑧 ) ) → ( ( Cntz ‘ 𝐺 ) ‘ ( ( 𝑥𝐼 ↦ { 0 } ) ‘ 𝑧 ) ) = ( ( Cntz ‘ 𝐺 ) ‘ { 0 } ) )
30 18 24 29 3sstr4d ( ( ( 𝐺 ∈ Grp ∧ 𝐼𝑉 ) ∧ ( 𝑦𝐼𝑧𝐼𝑦𝑧 ) ) → ( ( 𝑥𝐼 ↦ { 0 } ) ‘ 𝑦 ) ⊆ ( ( Cntz ‘ 𝐺 ) ‘ ( ( 𝑥𝐼 ↦ { 0 } ) ‘ 𝑧 ) ) )
31 23 adantl ( ( ( 𝐺 ∈ Grp ∧ 𝐼𝑉 ) ∧ 𝑦𝐼 ) → ( ( 𝑥𝐼 ↦ { 0 } ) ‘ 𝑦 ) = { 0 } )
32 31 ineq1d ( ( ( 𝐺 ∈ Grp ∧ 𝐼𝑉 ) ∧ 𝑦𝐼 ) → ( ( ( 𝑥𝐼 ↦ { 0 } ) ‘ 𝑦 ) ∩ ( ( mrCls ‘ ( SubGrp ‘ 𝐺 ) ) ‘ ( ( 𝑥𝐼 ↦ { 0 } ) “ ( 𝐼 ∖ { 𝑦 } ) ) ) ) = ( { 0 } ∩ ( ( mrCls ‘ ( SubGrp ‘ 𝐺 ) ) ‘ ( ( 𝑥𝐼 ↦ { 0 } ) “ ( 𝐼 ∖ { 𝑦 } ) ) ) ) )
33 9 subgacs ( 𝐺 ∈ Grp → ( SubGrp ‘ 𝐺 ) ∈ ( ACS ‘ ( Base ‘ 𝐺 ) ) )
34 33 ad2antrr ( ( ( 𝐺 ∈ Grp ∧ 𝐼𝑉 ) ∧ 𝑦𝐼 ) → ( SubGrp ‘ 𝐺 ) ∈ ( ACS ‘ ( Base ‘ 𝐺 ) ) )
35 34 acsmred ( ( ( 𝐺 ∈ Grp ∧ 𝐼𝑉 ) ∧ 𝑦𝐼 ) → ( SubGrp ‘ 𝐺 ) ∈ ( Moore ‘ ( Base ‘ 𝐺 ) ) )
36 imassrn ( ( 𝑥𝐼 ↦ { 0 } ) “ ( 𝐼 ∖ { 𝑦 } ) ) ⊆ ran ( 𝑥𝐼 ↦ { 0 } )
37 8 adantr ( ( ( 𝐺 ∈ Grp ∧ 𝐼𝑉 ) ∧ 𝑦𝐼 ) → ( 𝑥𝐼 ↦ { 0 } ) : 𝐼 ⟶ ( SubGrp ‘ 𝐺 ) )
38 37 frnd ( ( ( 𝐺 ∈ Grp ∧ 𝐼𝑉 ) ∧ 𝑦𝐼 ) → ran ( 𝑥𝐼 ↦ { 0 } ) ⊆ ( SubGrp ‘ 𝐺 ) )
39 mresspw ( ( SubGrp ‘ 𝐺 ) ∈ ( Moore ‘ ( Base ‘ 𝐺 ) ) → ( SubGrp ‘ 𝐺 ) ⊆ 𝒫 ( Base ‘ 𝐺 ) )
40 35 39 syl ( ( ( 𝐺 ∈ Grp ∧ 𝐼𝑉 ) ∧ 𝑦𝐼 ) → ( SubGrp ‘ 𝐺 ) ⊆ 𝒫 ( Base ‘ 𝐺 ) )
41 38 40 sstrd ( ( ( 𝐺 ∈ Grp ∧ 𝐼𝑉 ) ∧ 𝑦𝐼 ) → ran ( 𝑥𝐼 ↦ { 0 } ) ⊆ 𝒫 ( Base ‘ 𝐺 ) )
42 36 41 sstrid ( ( ( 𝐺 ∈ Grp ∧ 𝐼𝑉 ) ∧ 𝑦𝐼 ) → ( ( 𝑥𝐼 ↦ { 0 } ) “ ( 𝐼 ∖ { 𝑦 } ) ) ⊆ 𝒫 ( Base ‘ 𝐺 ) )
43 sspwuni ( ( ( 𝑥𝐼 ↦ { 0 } ) “ ( 𝐼 ∖ { 𝑦 } ) ) ⊆ 𝒫 ( Base ‘ 𝐺 ) ↔ ( ( 𝑥𝐼 ↦ { 0 } ) “ ( 𝐼 ∖ { 𝑦 } ) ) ⊆ ( Base ‘ 𝐺 ) )
44 42 43 sylib ( ( ( 𝐺 ∈ Grp ∧ 𝐼𝑉 ) ∧ 𝑦𝐼 ) → ( ( 𝑥𝐼 ↦ { 0 } ) “ ( 𝐼 ∖ { 𝑦 } ) ) ⊆ ( Base ‘ 𝐺 ) )
45 3 mrccl ( ( ( SubGrp ‘ 𝐺 ) ∈ ( Moore ‘ ( Base ‘ 𝐺 ) ) ∧ ( ( 𝑥𝐼 ↦ { 0 } ) “ ( 𝐼 ∖ { 𝑦 } ) ) ⊆ ( Base ‘ 𝐺 ) ) → ( ( mrCls ‘ ( SubGrp ‘ 𝐺 ) ) ‘ ( ( 𝑥𝐼 ↦ { 0 } ) “ ( 𝐼 ∖ { 𝑦 } ) ) ) ∈ ( SubGrp ‘ 𝐺 ) )
46 35 44 45 syl2anc ( ( ( 𝐺 ∈ Grp ∧ 𝐼𝑉 ) ∧ 𝑦𝐼 ) → ( ( mrCls ‘ ( SubGrp ‘ 𝐺 ) ) ‘ ( ( 𝑥𝐼 ↦ { 0 } ) “ ( 𝐼 ∖ { 𝑦 } ) ) ) ∈ ( SubGrp ‘ 𝐺 ) )
47 1 subg0cl ( ( ( mrCls ‘ ( SubGrp ‘ 𝐺 ) ) ‘ ( ( 𝑥𝐼 ↦ { 0 } ) “ ( 𝐼 ∖ { 𝑦 } ) ) ) ∈ ( SubGrp ‘ 𝐺 ) → 0 ∈ ( ( mrCls ‘ ( SubGrp ‘ 𝐺 ) ) ‘ ( ( 𝑥𝐼 ↦ { 0 } ) “ ( 𝐼 ∖ { 𝑦 } ) ) ) )
48 46 47 syl ( ( ( 𝐺 ∈ Grp ∧ 𝐼𝑉 ) ∧ 𝑦𝐼 ) → 0 ∈ ( ( mrCls ‘ ( SubGrp ‘ 𝐺 ) ) ‘ ( ( 𝑥𝐼 ↦ { 0 } ) “ ( 𝐼 ∖ { 𝑦 } ) ) ) )
49 48 snssd ( ( ( 𝐺 ∈ Grp ∧ 𝐼𝑉 ) ∧ 𝑦𝐼 ) → { 0 } ⊆ ( ( mrCls ‘ ( SubGrp ‘ 𝐺 ) ) ‘ ( ( 𝑥𝐼 ↦ { 0 } ) “ ( 𝐼 ∖ { 𝑦 } ) ) ) )
50 df-ss ( { 0 } ⊆ ( ( mrCls ‘ ( SubGrp ‘ 𝐺 ) ) ‘ ( ( 𝑥𝐼 ↦ { 0 } ) “ ( 𝐼 ∖ { 𝑦 } ) ) ) ↔ ( { 0 } ∩ ( ( mrCls ‘ ( SubGrp ‘ 𝐺 ) ) ‘ ( ( 𝑥𝐼 ↦ { 0 } ) “ ( 𝐼 ∖ { 𝑦 } ) ) ) ) = { 0 } )
51 49 50 sylib ( ( ( 𝐺 ∈ Grp ∧ 𝐼𝑉 ) ∧ 𝑦𝐼 ) → ( { 0 } ∩ ( ( mrCls ‘ ( SubGrp ‘ 𝐺 ) ) ‘ ( ( 𝑥𝐼 ↦ { 0 } ) “ ( 𝐼 ∖ { 𝑦 } ) ) ) ) = { 0 } )
52 32 51 eqtrd ( ( ( 𝐺 ∈ Grp ∧ 𝐼𝑉 ) ∧ 𝑦𝐼 ) → ( ( ( 𝑥𝐼 ↦ { 0 } ) ‘ 𝑦 ) ∩ ( ( mrCls ‘ ( SubGrp ‘ 𝐺 ) ) ‘ ( ( 𝑥𝐼 ↦ { 0 } ) “ ( 𝐼 ∖ { 𝑦 } ) ) ) ) = { 0 } )
53 eqimss ( ( ( ( 𝑥𝐼 ↦ { 0 } ) ‘ 𝑦 ) ∩ ( ( mrCls ‘ ( SubGrp ‘ 𝐺 ) ) ‘ ( ( 𝑥𝐼 ↦ { 0 } ) “ ( 𝐼 ∖ { 𝑦 } ) ) ) ) = { 0 } → ( ( ( 𝑥𝐼 ↦ { 0 } ) ‘ 𝑦 ) ∩ ( ( mrCls ‘ ( SubGrp ‘ 𝐺 ) ) ‘ ( ( 𝑥𝐼 ↦ { 0 } ) “ ( 𝐼 ∖ { 𝑦 } ) ) ) ) ⊆ { 0 } )
54 52 53 syl ( ( ( 𝐺 ∈ Grp ∧ 𝐼𝑉 ) ∧ 𝑦𝐼 ) → ( ( ( 𝑥𝐼 ↦ { 0 } ) ‘ 𝑦 ) ∩ ( ( mrCls ‘ ( SubGrp ‘ 𝐺 ) ) ‘ ( ( 𝑥𝐼 ↦ { 0 } ) “ ( 𝐼 ∖ { 𝑦 } ) ) ) ) ⊆ { 0 } )
55 2 1 3 4 5 8 30 54 dmdprdd ( ( 𝐺 ∈ Grp ∧ 𝐼𝑉 ) → 𝐺 dom DProd ( 𝑥𝐼 ↦ { 0 } ) )
56 21 7 dmmptd ( ( 𝐺 ∈ Grp ∧ 𝐼𝑉 ) → dom ( 𝑥𝐼 ↦ { 0 } ) = 𝐼 )
57 6 adantr ( ( 𝐺 ∈ Grp ∧ 𝐼𝑉 ) → { 0 } ∈ ( SubGrp ‘ 𝐺 ) )
58 eqimss ( ( ( 𝑥𝐼 ↦ { 0 } ) ‘ 𝑦 ) = { 0 } → ( ( 𝑥𝐼 ↦ { 0 } ) ‘ 𝑦 ) ⊆ { 0 } )
59 31 58 syl ( ( ( 𝐺 ∈ Grp ∧ 𝐼𝑉 ) ∧ 𝑦𝐼 ) → ( ( 𝑥𝐼 ↦ { 0 } ) ‘ 𝑦 ) ⊆ { 0 } )
60 55 56 57 59 dprdlub ( ( 𝐺 ∈ Grp ∧ 𝐼𝑉 ) → ( 𝐺 DProd ( 𝑥𝐼 ↦ { 0 } ) ) ⊆ { 0 } )
61 dprdsubg ( 𝐺 dom DProd ( 𝑥𝐼 ↦ { 0 } ) → ( 𝐺 DProd ( 𝑥𝐼 ↦ { 0 } ) ) ∈ ( SubGrp ‘ 𝐺 ) )
62 1 subg0cl ( ( 𝐺 DProd ( 𝑥𝐼 ↦ { 0 } ) ) ∈ ( SubGrp ‘ 𝐺 ) → 0 ∈ ( 𝐺 DProd ( 𝑥𝐼 ↦ { 0 } ) ) )
63 55 61 62 3syl ( ( 𝐺 ∈ Grp ∧ 𝐼𝑉 ) → 0 ∈ ( 𝐺 DProd ( 𝑥𝐼 ↦ { 0 } ) ) )
64 63 snssd ( ( 𝐺 ∈ Grp ∧ 𝐼𝑉 ) → { 0 } ⊆ ( 𝐺 DProd ( 𝑥𝐼 ↦ { 0 } ) ) )
65 60 64 eqssd ( ( 𝐺 ∈ Grp ∧ 𝐼𝑉 ) → ( 𝐺 DProd ( 𝑥𝐼 ↦ { 0 } ) ) = { 0 } )
66 55 65 jca ( ( 𝐺 ∈ Grp ∧ 𝐼𝑉 ) → ( 𝐺 dom DProd ( 𝑥𝐼 ↦ { 0 } ) ∧ ( 𝐺 DProd ( 𝑥𝐼 ↦ { 0 } ) ) = { 0 } ) )