Metamath Proof Explorer


Theorem lsmsubm

Description: The sum of two commuting submonoids is a submonoid. (Contributed by Mario Carneiro, 19-Apr-2016)

Ref Expression
Hypotheses lsmsubg.p = ( LSSum ‘ 𝐺 )
lsmsubg.z 𝑍 = ( Cntz ‘ 𝐺 )
Assertion lsmsubm ( ( 𝑇 ∈ ( SubMnd ‘ 𝐺 ) ∧ 𝑈 ∈ ( SubMnd ‘ 𝐺 ) ∧ 𝑇 ⊆ ( 𝑍𝑈 ) ) → ( 𝑇 𝑈 ) ∈ ( SubMnd ‘ 𝐺 ) )

Proof

Step Hyp Ref Expression
1 lsmsubg.p = ( LSSum ‘ 𝐺 )
2 lsmsubg.z 𝑍 = ( Cntz ‘ 𝐺 )
3 submrcl ( 𝑇 ∈ ( SubMnd ‘ 𝐺 ) → 𝐺 ∈ Mnd )
4 3 3ad2ant1 ( ( 𝑇 ∈ ( SubMnd ‘ 𝐺 ) ∧ 𝑈 ∈ ( SubMnd ‘ 𝐺 ) ∧ 𝑇 ⊆ ( 𝑍𝑈 ) ) → 𝐺 ∈ Mnd )
5 eqid ( Base ‘ 𝐺 ) = ( Base ‘ 𝐺 )
6 5 submss ( 𝑇 ∈ ( SubMnd ‘ 𝐺 ) → 𝑇 ⊆ ( Base ‘ 𝐺 ) )
7 6 3ad2ant1 ( ( 𝑇 ∈ ( SubMnd ‘ 𝐺 ) ∧ 𝑈 ∈ ( SubMnd ‘ 𝐺 ) ∧ 𝑇 ⊆ ( 𝑍𝑈 ) ) → 𝑇 ⊆ ( Base ‘ 𝐺 ) )
8 5 submss ( 𝑈 ∈ ( SubMnd ‘ 𝐺 ) → 𝑈 ⊆ ( Base ‘ 𝐺 ) )
9 8 3ad2ant2 ( ( 𝑇 ∈ ( SubMnd ‘ 𝐺 ) ∧ 𝑈 ∈ ( SubMnd ‘ 𝐺 ) ∧ 𝑇 ⊆ ( 𝑍𝑈 ) ) → 𝑈 ⊆ ( Base ‘ 𝐺 ) )
10 5 1 lsmssv ( ( 𝐺 ∈ Mnd ∧ 𝑇 ⊆ ( Base ‘ 𝐺 ) ∧ 𝑈 ⊆ ( Base ‘ 𝐺 ) ) → ( 𝑇 𝑈 ) ⊆ ( Base ‘ 𝐺 ) )
11 4 7 9 10 syl3anc ( ( 𝑇 ∈ ( SubMnd ‘ 𝐺 ) ∧ 𝑈 ∈ ( SubMnd ‘ 𝐺 ) ∧ 𝑇 ⊆ ( 𝑍𝑈 ) ) → ( 𝑇 𝑈 ) ⊆ ( Base ‘ 𝐺 ) )
12 simp2 ( ( 𝑇 ∈ ( SubMnd ‘ 𝐺 ) ∧ 𝑈 ∈ ( SubMnd ‘ 𝐺 ) ∧ 𝑇 ⊆ ( 𝑍𝑈 ) ) → 𝑈 ∈ ( SubMnd ‘ 𝐺 ) )
13 5 1 lsmub1x ( ( 𝑇 ⊆ ( Base ‘ 𝐺 ) ∧ 𝑈 ∈ ( SubMnd ‘ 𝐺 ) ) → 𝑇 ⊆ ( 𝑇 𝑈 ) )
14 7 12 13 syl2anc ( ( 𝑇 ∈ ( SubMnd ‘ 𝐺 ) ∧ 𝑈 ∈ ( SubMnd ‘ 𝐺 ) ∧ 𝑇 ⊆ ( 𝑍𝑈 ) ) → 𝑇 ⊆ ( 𝑇 𝑈 ) )
15 eqid ( 0g𝐺 ) = ( 0g𝐺 )
16 15 subm0cl ( 𝑇 ∈ ( SubMnd ‘ 𝐺 ) → ( 0g𝐺 ) ∈ 𝑇 )
17 16 3ad2ant1 ( ( 𝑇 ∈ ( SubMnd ‘ 𝐺 ) ∧ 𝑈 ∈ ( SubMnd ‘ 𝐺 ) ∧ 𝑇 ⊆ ( 𝑍𝑈 ) ) → ( 0g𝐺 ) ∈ 𝑇 )
18 14 17 sseldd ( ( 𝑇 ∈ ( SubMnd ‘ 𝐺 ) ∧ 𝑈 ∈ ( SubMnd ‘ 𝐺 ) ∧ 𝑇 ⊆ ( 𝑍𝑈 ) ) → ( 0g𝐺 ) ∈ ( 𝑇 𝑈 ) )
19 eqid ( +g𝐺 ) = ( +g𝐺 )
20 5 19 1 lsmelvalx ( ( 𝐺 ∈ Mnd ∧ 𝑇 ⊆ ( Base ‘ 𝐺 ) ∧ 𝑈 ⊆ ( Base ‘ 𝐺 ) ) → ( 𝑥 ∈ ( 𝑇 𝑈 ) ↔ ∃ 𝑎𝑇𝑐𝑈 𝑥 = ( 𝑎 ( +g𝐺 ) 𝑐 ) ) )
21 4 7 9 20 syl3anc ( ( 𝑇 ∈ ( SubMnd ‘ 𝐺 ) ∧ 𝑈 ∈ ( SubMnd ‘ 𝐺 ) ∧ 𝑇 ⊆ ( 𝑍𝑈 ) ) → ( 𝑥 ∈ ( 𝑇 𝑈 ) ↔ ∃ 𝑎𝑇𝑐𝑈 𝑥 = ( 𝑎 ( +g𝐺 ) 𝑐 ) ) )
22 5 19 1 lsmelvalx ( ( 𝐺 ∈ Mnd ∧ 𝑇 ⊆ ( Base ‘ 𝐺 ) ∧ 𝑈 ⊆ ( Base ‘ 𝐺 ) ) → ( 𝑦 ∈ ( 𝑇 𝑈 ) ↔ ∃ 𝑏𝑇𝑑𝑈 𝑦 = ( 𝑏 ( +g𝐺 ) 𝑑 ) ) )
23 4 7 9 22 syl3anc ( ( 𝑇 ∈ ( SubMnd ‘ 𝐺 ) ∧ 𝑈 ∈ ( SubMnd ‘ 𝐺 ) ∧ 𝑇 ⊆ ( 𝑍𝑈 ) ) → ( 𝑦 ∈ ( 𝑇 𝑈 ) ↔ ∃ 𝑏𝑇𝑑𝑈 𝑦 = ( 𝑏 ( +g𝐺 ) 𝑑 ) ) )
24 21 23 anbi12d ( ( 𝑇 ∈ ( SubMnd ‘ 𝐺 ) ∧ 𝑈 ∈ ( SubMnd ‘ 𝐺 ) ∧ 𝑇 ⊆ ( 𝑍𝑈 ) ) → ( ( 𝑥 ∈ ( 𝑇 𝑈 ) ∧ 𝑦 ∈ ( 𝑇 𝑈 ) ) ↔ ( ∃ 𝑎𝑇𝑐𝑈 𝑥 = ( 𝑎 ( +g𝐺 ) 𝑐 ) ∧ ∃ 𝑏𝑇𝑑𝑈 𝑦 = ( 𝑏 ( +g𝐺 ) 𝑑 ) ) ) )
25 reeanv ( ∃ 𝑎𝑇𝑏𝑇 ( ∃ 𝑐𝑈 𝑥 = ( 𝑎 ( +g𝐺 ) 𝑐 ) ∧ ∃ 𝑑𝑈 𝑦 = ( 𝑏 ( +g𝐺 ) 𝑑 ) ) ↔ ( ∃ 𝑎𝑇𝑐𝑈 𝑥 = ( 𝑎 ( +g𝐺 ) 𝑐 ) ∧ ∃ 𝑏𝑇𝑑𝑈 𝑦 = ( 𝑏 ( +g𝐺 ) 𝑑 ) ) )
26 reeanv ( ∃ 𝑐𝑈𝑑𝑈 ( 𝑥 = ( 𝑎 ( +g𝐺 ) 𝑐 ) ∧ 𝑦 = ( 𝑏 ( +g𝐺 ) 𝑑 ) ) ↔ ( ∃ 𝑐𝑈 𝑥 = ( 𝑎 ( +g𝐺 ) 𝑐 ) ∧ ∃ 𝑑𝑈 𝑦 = ( 𝑏 ( +g𝐺 ) 𝑑 ) ) )
27 4 adantr ( ( ( 𝑇 ∈ ( SubMnd ‘ 𝐺 ) ∧ 𝑈 ∈ ( SubMnd ‘ 𝐺 ) ∧ 𝑇 ⊆ ( 𝑍𝑈 ) ) ∧ ( ( 𝑎𝑇𝑏𝑇 ) ∧ ( 𝑐𝑈𝑑𝑈 ) ) ) → 𝐺 ∈ Mnd )
28 7 adantr ( ( ( 𝑇 ∈ ( SubMnd ‘ 𝐺 ) ∧ 𝑈 ∈ ( SubMnd ‘ 𝐺 ) ∧ 𝑇 ⊆ ( 𝑍𝑈 ) ) ∧ ( ( 𝑎𝑇𝑏𝑇 ) ∧ ( 𝑐𝑈𝑑𝑈 ) ) ) → 𝑇 ⊆ ( Base ‘ 𝐺 ) )
29 simprll ( ( ( 𝑇 ∈ ( SubMnd ‘ 𝐺 ) ∧ 𝑈 ∈ ( SubMnd ‘ 𝐺 ) ∧ 𝑇 ⊆ ( 𝑍𝑈 ) ) ∧ ( ( 𝑎𝑇𝑏𝑇 ) ∧ ( 𝑐𝑈𝑑𝑈 ) ) ) → 𝑎𝑇 )
30 28 29 sseldd ( ( ( 𝑇 ∈ ( SubMnd ‘ 𝐺 ) ∧ 𝑈 ∈ ( SubMnd ‘ 𝐺 ) ∧ 𝑇 ⊆ ( 𝑍𝑈 ) ) ∧ ( ( 𝑎𝑇𝑏𝑇 ) ∧ ( 𝑐𝑈𝑑𝑈 ) ) ) → 𝑎 ∈ ( Base ‘ 𝐺 ) )
31 simprlr ( ( ( 𝑇 ∈ ( SubMnd ‘ 𝐺 ) ∧ 𝑈 ∈ ( SubMnd ‘ 𝐺 ) ∧ 𝑇 ⊆ ( 𝑍𝑈 ) ) ∧ ( ( 𝑎𝑇𝑏𝑇 ) ∧ ( 𝑐𝑈𝑑𝑈 ) ) ) → 𝑏𝑇 )
32 28 31 sseldd ( ( ( 𝑇 ∈ ( SubMnd ‘ 𝐺 ) ∧ 𝑈 ∈ ( SubMnd ‘ 𝐺 ) ∧ 𝑇 ⊆ ( 𝑍𝑈 ) ) ∧ ( ( 𝑎𝑇𝑏𝑇 ) ∧ ( 𝑐𝑈𝑑𝑈 ) ) ) → 𝑏 ∈ ( Base ‘ 𝐺 ) )
33 9 adantr ( ( ( 𝑇 ∈ ( SubMnd ‘ 𝐺 ) ∧ 𝑈 ∈ ( SubMnd ‘ 𝐺 ) ∧ 𝑇 ⊆ ( 𝑍𝑈 ) ) ∧ ( ( 𝑎𝑇𝑏𝑇 ) ∧ ( 𝑐𝑈𝑑𝑈 ) ) ) → 𝑈 ⊆ ( Base ‘ 𝐺 ) )
34 simprrl ( ( ( 𝑇 ∈ ( SubMnd ‘ 𝐺 ) ∧ 𝑈 ∈ ( SubMnd ‘ 𝐺 ) ∧ 𝑇 ⊆ ( 𝑍𝑈 ) ) ∧ ( ( 𝑎𝑇𝑏𝑇 ) ∧ ( 𝑐𝑈𝑑𝑈 ) ) ) → 𝑐𝑈 )
35 33 34 sseldd ( ( ( 𝑇 ∈ ( SubMnd ‘ 𝐺 ) ∧ 𝑈 ∈ ( SubMnd ‘ 𝐺 ) ∧ 𝑇 ⊆ ( 𝑍𝑈 ) ) ∧ ( ( 𝑎𝑇𝑏𝑇 ) ∧ ( 𝑐𝑈𝑑𝑈 ) ) ) → 𝑐 ∈ ( Base ‘ 𝐺 ) )
36 simprrr ( ( ( 𝑇 ∈ ( SubMnd ‘ 𝐺 ) ∧ 𝑈 ∈ ( SubMnd ‘ 𝐺 ) ∧ 𝑇 ⊆ ( 𝑍𝑈 ) ) ∧ ( ( 𝑎𝑇𝑏𝑇 ) ∧ ( 𝑐𝑈𝑑𝑈 ) ) ) → 𝑑𝑈 )
37 33 36 sseldd ( ( ( 𝑇 ∈ ( SubMnd ‘ 𝐺 ) ∧ 𝑈 ∈ ( SubMnd ‘ 𝐺 ) ∧ 𝑇 ⊆ ( 𝑍𝑈 ) ) ∧ ( ( 𝑎𝑇𝑏𝑇 ) ∧ ( 𝑐𝑈𝑑𝑈 ) ) ) → 𝑑 ∈ ( Base ‘ 𝐺 ) )
38 simpl3 ( ( ( 𝑇 ∈ ( SubMnd ‘ 𝐺 ) ∧ 𝑈 ∈ ( SubMnd ‘ 𝐺 ) ∧ 𝑇 ⊆ ( 𝑍𝑈 ) ) ∧ ( ( 𝑎𝑇𝑏𝑇 ) ∧ ( 𝑐𝑈𝑑𝑈 ) ) ) → 𝑇 ⊆ ( 𝑍𝑈 ) )
39 38 31 sseldd ( ( ( 𝑇 ∈ ( SubMnd ‘ 𝐺 ) ∧ 𝑈 ∈ ( SubMnd ‘ 𝐺 ) ∧ 𝑇 ⊆ ( 𝑍𝑈 ) ) ∧ ( ( 𝑎𝑇𝑏𝑇 ) ∧ ( 𝑐𝑈𝑑𝑈 ) ) ) → 𝑏 ∈ ( 𝑍𝑈 ) )
40 19 2 cntzi ( ( 𝑏 ∈ ( 𝑍𝑈 ) ∧ 𝑐𝑈 ) → ( 𝑏 ( +g𝐺 ) 𝑐 ) = ( 𝑐 ( +g𝐺 ) 𝑏 ) )
41 39 34 40 syl2anc ( ( ( 𝑇 ∈ ( SubMnd ‘ 𝐺 ) ∧ 𝑈 ∈ ( SubMnd ‘ 𝐺 ) ∧ 𝑇 ⊆ ( 𝑍𝑈 ) ) ∧ ( ( 𝑎𝑇𝑏𝑇 ) ∧ ( 𝑐𝑈𝑑𝑈 ) ) ) → ( 𝑏 ( +g𝐺 ) 𝑐 ) = ( 𝑐 ( +g𝐺 ) 𝑏 ) )
42 5 19 27 30 32 35 37 41 mnd4g ( ( ( 𝑇 ∈ ( SubMnd ‘ 𝐺 ) ∧ 𝑈 ∈ ( SubMnd ‘ 𝐺 ) ∧ 𝑇 ⊆ ( 𝑍𝑈 ) ) ∧ ( ( 𝑎𝑇𝑏𝑇 ) ∧ ( 𝑐𝑈𝑑𝑈 ) ) ) → ( ( 𝑎 ( +g𝐺 ) 𝑏 ) ( +g𝐺 ) ( 𝑐 ( +g𝐺 ) 𝑑 ) ) = ( ( 𝑎 ( +g𝐺 ) 𝑐 ) ( +g𝐺 ) ( 𝑏 ( +g𝐺 ) 𝑑 ) ) )
43 simpl1 ( ( ( 𝑇 ∈ ( SubMnd ‘ 𝐺 ) ∧ 𝑈 ∈ ( SubMnd ‘ 𝐺 ) ∧ 𝑇 ⊆ ( 𝑍𝑈 ) ) ∧ ( ( 𝑎𝑇𝑏𝑇 ) ∧ ( 𝑐𝑈𝑑𝑈 ) ) ) → 𝑇 ∈ ( SubMnd ‘ 𝐺 ) )
44 19 submcl ( ( 𝑇 ∈ ( SubMnd ‘ 𝐺 ) ∧ 𝑎𝑇𝑏𝑇 ) → ( 𝑎 ( +g𝐺 ) 𝑏 ) ∈ 𝑇 )
45 43 29 31 44 syl3anc ( ( ( 𝑇 ∈ ( SubMnd ‘ 𝐺 ) ∧ 𝑈 ∈ ( SubMnd ‘ 𝐺 ) ∧ 𝑇 ⊆ ( 𝑍𝑈 ) ) ∧ ( ( 𝑎𝑇𝑏𝑇 ) ∧ ( 𝑐𝑈𝑑𝑈 ) ) ) → ( 𝑎 ( +g𝐺 ) 𝑏 ) ∈ 𝑇 )
46 simpl2 ( ( ( 𝑇 ∈ ( SubMnd ‘ 𝐺 ) ∧ 𝑈 ∈ ( SubMnd ‘ 𝐺 ) ∧ 𝑇 ⊆ ( 𝑍𝑈 ) ) ∧ ( ( 𝑎𝑇𝑏𝑇 ) ∧ ( 𝑐𝑈𝑑𝑈 ) ) ) → 𝑈 ∈ ( SubMnd ‘ 𝐺 ) )
47 19 submcl ( ( 𝑈 ∈ ( SubMnd ‘ 𝐺 ) ∧ 𝑐𝑈𝑑𝑈 ) → ( 𝑐 ( +g𝐺 ) 𝑑 ) ∈ 𝑈 )
48 46 34 36 47 syl3anc ( ( ( 𝑇 ∈ ( SubMnd ‘ 𝐺 ) ∧ 𝑈 ∈ ( SubMnd ‘ 𝐺 ) ∧ 𝑇 ⊆ ( 𝑍𝑈 ) ) ∧ ( ( 𝑎𝑇𝑏𝑇 ) ∧ ( 𝑐𝑈𝑑𝑈 ) ) ) → ( 𝑐 ( +g𝐺 ) 𝑑 ) ∈ 𝑈 )
49 5 19 1 lsmelvalix ( ( ( 𝐺 ∈ Mnd ∧ 𝑇 ⊆ ( Base ‘ 𝐺 ) ∧ 𝑈 ⊆ ( Base ‘ 𝐺 ) ) ∧ ( ( 𝑎 ( +g𝐺 ) 𝑏 ) ∈ 𝑇 ∧ ( 𝑐 ( +g𝐺 ) 𝑑 ) ∈ 𝑈 ) ) → ( ( 𝑎 ( +g𝐺 ) 𝑏 ) ( +g𝐺 ) ( 𝑐 ( +g𝐺 ) 𝑑 ) ) ∈ ( 𝑇 𝑈 ) )
50 27 28 33 45 48 49 syl32anc ( ( ( 𝑇 ∈ ( SubMnd ‘ 𝐺 ) ∧ 𝑈 ∈ ( SubMnd ‘ 𝐺 ) ∧ 𝑇 ⊆ ( 𝑍𝑈 ) ) ∧ ( ( 𝑎𝑇𝑏𝑇 ) ∧ ( 𝑐𝑈𝑑𝑈 ) ) ) → ( ( 𝑎 ( +g𝐺 ) 𝑏 ) ( +g𝐺 ) ( 𝑐 ( +g𝐺 ) 𝑑 ) ) ∈ ( 𝑇 𝑈 ) )
51 42 50 eqeltrrd ( ( ( 𝑇 ∈ ( SubMnd ‘ 𝐺 ) ∧ 𝑈 ∈ ( SubMnd ‘ 𝐺 ) ∧ 𝑇 ⊆ ( 𝑍𝑈 ) ) ∧ ( ( 𝑎𝑇𝑏𝑇 ) ∧ ( 𝑐𝑈𝑑𝑈 ) ) ) → ( ( 𝑎 ( +g𝐺 ) 𝑐 ) ( +g𝐺 ) ( 𝑏 ( +g𝐺 ) 𝑑 ) ) ∈ ( 𝑇 𝑈 ) )
52 oveq12 ( ( 𝑥 = ( 𝑎 ( +g𝐺 ) 𝑐 ) ∧ 𝑦 = ( 𝑏 ( +g𝐺 ) 𝑑 ) ) → ( 𝑥 ( +g𝐺 ) 𝑦 ) = ( ( 𝑎 ( +g𝐺 ) 𝑐 ) ( +g𝐺 ) ( 𝑏 ( +g𝐺 ) 𝑑 ) ) )
53 52 eleq1d ( ( 𝑥 = ( 𝑎 ( +g𝐺 ) 𝑐 ) ∧ 𝑦 = ( 𝑏 ( +g𝐺 ) 𝑑 ) ) → ( ( 𝑥 ( +g𝐺 ) 𝑦 ) ∈ ( 𝑇 𝑈 ) ↔ ( ( 𝑎 ( +g𝐺 ) 𝑐 ) ( +g𝐺 ) ( 𝑏 ( +g𝐺 ) 𝑑 ) ) ∈ ( 𝑇 𝑈 ) ) )
54 51 53 syl5ibrcom ( ( ( 𝑇 ∈ ( SubMnd ‘ 𝐺 ) ∧ 𝑈 ∈ ( SubMnd ‘ 𝐺 ) ∧ 𝑇 ⊆ ( 𝑍𝑈 ) ) ∧ ( ( 𝑎𝑇𝑏𝑇 ) ∧ ( 𝑐𝑈𝑑𝑈 ) ) ) → ( ( 𝑥 = ( 𝑎 ( +g𝐺 ) 𝑐 ) ∧ 𝑦 = ( 𝑏 ( +g𝐺 ) 𝑑 ) ) → ( 𝑥 ( +g𝐺 ) 𝑦 ) ∈ ( 𝑇 𝑈 ) ) )
55 54 anassrs ( ( ( ( 𝑇 ∈ ( SubMnd ‘ 𝐺 ) ∧ 𝑈 ∈ ( SubMnd ‘ 𝐺 ) ∧ 𝑇 ⊆ ( 𝑍𝑈 ) ) ∧ ( 𝑎𝑇𝑏𝑇 ) ) ∧ ( 𝑐𝑈𝑑𝑈 ) ) → ( ( 𝑥 = ( 𝑎 ( +g𝐺 ) 𝑐 ) ∧ 𝑦 = ( 𝑏 ( +g𝐺 ) 𝑑 ) ) → ( 𝑥 ( +g𝐺 ) 𝑦 ) ∈ ( 𝑇 𝑈 ) ) )
56 55 rexlimdvva ( ( ( 𝑇 ∈ ( SubMnd ‘ 𝐺 ) ∧ 𝑈 ∈ ( SubMnd ‘ 𝐺 ) ∧ 𝑇 ⊆ ( 𝑍𝑈 ) ) ∧ ( 𝑎𝑇𝑏𝑇 ) ) → ( ∃ 𝑐𝑈𝑑𝑈 ( 𝑥 = ( 𝑎 ( +g𝐺 ) 𝑐 ) ∧ 𝑦 = ( 𝑏 ( +g𝐺 ) 𝑑 ) ) → ( 𝑥 ( +g𝐺 ) 𝑦 ) ∈ ( 𝑇 𝑈 ) ) )
57 26 56 syl5bir ( ( ( 𝑇 ∈ ( SubMnd ‘ 𝐺 ) ∧ 𝑈 ∈ ( SubMnd ‘ 𝐺 ) ∧ 𝑇 ⊆ ( 𝑍𝑈 ) ) ∧ ( 𝑎𝑇𝑏𝑇 ) ) → ( ( ∃ 𝑐𝑈 𝑥 = ( 𝑎 ( +g𝐺 ) 𝑐 ) ∧ ∃ 𝑑𝑈 𝑦 = ( 𝑏 ( +g𝐺 ) 𝑑 ) ) → ( 𝑥 ( +g𝐺 ) 𝑦 ) ∈ ( 𝑇 𝑈 ) ) )
58 57 rexlimdvva ( ( 𝑇 ∈ ( SubMnd ‘ 𝐺 ) ∧ 𝑈 ∈ ( SubMnd ‘ 𝐺 ) ∧ 𝑇 ⊆ ( 𝑍𝑈 ) ) → ( ∃ 𝑎𝑇𝑏𝑇 ( ∃ 𝑐𝑈 𝑥 = ( 𝑎 ( +g𝐺 ) 𝑐 ) ∧ ∃ 𝑑𝑈 𝑦 = ( 𝑏 ( +g𝐺 ) 𝑑 ) ) → ( 𝑥 ( +g𝐺 ) 𝑦 ) ∈ ( 𝑇 𝑈 ) ) )
59 25 58 syl5bir ( ( 𝑇 ∈ ( SubMnd ‘ 𝐺 ) ∧ 𝑈 ∈ ( SubMnd ‘ 𝐺 ) ∧ 𝑇 ⊆ ( 𝑍𝑈 ) ) → ( ( ∃ 𝑎𝑇𝑐𝑈 𝑥 = ( 𝑎 ( +g𝐺 ) 𝑐 ) ∧ ∃ 𝑏𝑇𝑑𝑈 𝑦 = ( 𝑏 ( +g𝐺 ) 𝑑 ) ) → ( 𝑥 ( +g𝐺 ) 𝑦 ) ∈ ( 𝑇 𝑈 ) ) )
60 24 59 sylbid ( ( 𝑇 ∈ ( SubMnd ‘ 𝐺 ) ∧ 𝑈 ∈ ( SubMnd ‘ 𝐺 ) ∧ 𝑇 ⊆ ( 𝑍𝑈 ) ) → ( ( 𝑥 ∈ ( 𝑇 𝑈 ) ∧ 𝑦 ∈ ( 𝑇 𝑈 ) ) → ( 𝑥 ( +g𝐺 ) 𝑦 ) ∈ ( 𝑇 𝑈 ) ) )
61 60 ralrimivv ( ( 𝑇 ∈ ( SubMnd ‘ 𝐺 ) ∧ 𝑈 ∈ ( SubMnd ‘ 𝐺 ) ∧ 𝑇 ⊆ ( 𝑍𝑈 ) ) → ∀ 𝑥 ∈ ( 𝑇 𝑈 ) ∀ 𝑦 ∈ ( 𝑇 𝑈 ) ( 𝑥 ( +g𝐺 ) 𝑦 ) ∈ ( 𝑇 𝑈 ) )
62 5 15 19 issubm ( 𝐺 ∈ Mnd → ( ( 𝑇 𝑈 ) ∈ ( SubMnd ‘ 𝐺 ) ↔ ( ( 𝑇 𝑈 ) ⊆ ( Base ‘ 𝐺 ) ∧ ( 0g𝐺 ) ∈ ( 𝑇 𝑈 ) ∧ ∀ 𝑥 ∈ ( 𝑇 𝑈 ) ∀ 𝑦 ∈ ( 𝑇 𝑈 ) ( 𝑥 ( +g𝐺 ) 𝑦 ) ∈ ( 𝑇 𝑈 ) ) ) )
63 4 62 syl ( ( 𝑇 ∈ ( SubMnd ‘ 𝐺 ) ∧ 𝑈 ∈ ( SubMnd ‘ 𝐺 ) ∧ 𝑇 ⊆ ( 𝑍𝑈 ) ) → ( ( 𝑇 𝑈 ) ∈ ( SubMnd ‘ 𝐺 ) ↔ ( ( 𝑇 𝑈 ) ⊆ ( Base ‘ 𝐺 ) ∧ ( 0g𝐺 ) ∈ ( 𝑇 𝑈 ) ∧ ∀ 𝑥 ∈ ( 𝑇 𝑈 ) ∀ 𝑦 ∈ ( 𝑇 𝑈 ) ( 𝑥 ( +g𝐺 ) 𝑦 ) ∈ ( 𝑇 𝑈 ) ) ) )
64 11 18 61 63 mpbir3and ( ( 𝑇 ∈ ( SubMnd ‘ 𝐺 ) ∧ 𝑈 ∈ ( SubMnd ‘ 𝐺 ) ∧ 𝑇 ⊆ ( 𝑍𝑈 ) ) → ( 𝑇 𝑈 ) ∈ ( SubMnd ‘ 𝐺 ) )