Theorem lsmsubg 19355

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

Hypotheses

Ref	Expression
lsmsubg.p	⊢ ⊕ = (LSSum‘𝐺)
lsmsubg.z	⊢ 𝑍 = (Cntz‘𝐺)

Assertion

Ref	Expression
lsmsubg	⊢ ((𝑇 ∈ (SubGrp‘𝐺) ∧ 𝑈 ∈ (SubGrp‘𝐺) ∧ 𝑇 ⊆ (𝑍‘𝑈)) → (𝑇 ⊕ 𝑈) ∈ (SubGrp‘𝐺))

Proof of Theorem lsmsubg

Dummy variables 𝑎 𝑏 𝑥 are mutually distinct and distinct from all other variables.

Step	Hyp	Ref	Expression
1		simp1 1136	. . . 4 ⊢ ((𝑇 ∈ (SubGrp‘𝐺) ∧ 𝑈 ∈ (SubGrp‘𝐺) ∧ 𝑇 ⊆ (𝑍‘𝑈)) → 𝑇 ∈ (SubGrp‘𝐺))
2		subgsubm 18873	. . . 4 ⊢ (𝑇 ∈ (SubGrp‘𝐺) → 𝑇 ∈ (SubMnd‘𝐺))
3	1, 2	syl 17	. . 3 ⊢ ((𝑇 ∈ (SubGrp‘𝐺) ∧ 𝑈 ∈ (SubGrp‘𝐺) ∧ 𝑇 ⊆ (𝑍‘𝑈)) → 𝑇 ∈ (SubMnd‘𝐺))
4		simp2 1137	. . . 4 ⊢ ((𝑇 ∈ (SubGrp‘𝐺) ∧ 𝑈 ∈ (SubGrp‘𝐺) ∧ 𝑇 ⊆ (𝑍‘𝑈)) → 𝑈 ∈ (SubGrp‘𝐺))
5		subgsubm 18873	. . . 4 ⊢ (𝑈 ∈ (SubGrp‘𝐺) → 𝑈 ∈ (SubMnd‘𝐺))
6	4, 5	syl 17	. . 3 ⊢ ((𝑇 ∈ (SubGrp‘𝐺) ∧ 𝑈 ∈ (SubGrp‘𝐺) ∧ 𝑇 ⊆ (𝑍‘𝑈)) → 𝑈 ∈ (SubMnd‘𝐺))
7		simp3 1138	. . 3 ⊢ ((𝑇 ∈ (SubGrp‘𝐺) ∧ 𝑈 ∈ (SubGrp‘𝐺) ∧ 𝑇 ⊆ (𝑍‘𝑈)) → 𝑇 ⊆ (𝑍‘𝑈))
8		lsmsubg.p	. . . 4 ⊢ ⊕ = (LSSum‘𝐺)
9		lsmsubg.z	. . . 4 ⊢ 𝑍 = (Cntz‘𝐺)
10	8, 9	lsmsubm 19354	. . 3 ⊢ ((𝑇 ∈ (SubMnd‘𝐺) ∧ 𝑈 ∈ (SubMnd‘𝐺) ∧ 𝑇 ⊆ (𝑍‘𝑈)) → (𝑇 ⊕ 𝑈) ∈ (SubMnd‘𝐺))
11	3, 6, 7, 10	syl3anc 1371	. 2 ⊢ ((𝑇 ∈ (SubGrp‘𝐺) ∧ 𝑈 ∈ (SubGrp‘𝐺) ∧ 𝑇 ⊆ (𝑍‘𝑈)) → (𝑇 ⊕ 𝑈) ∈ (SubMnd‘𝐺))
12		eqid 2737	. . . . . 6 ⊢ (+g‘𝐺) = (+g‘𝐺)
13	12, 8	lsmelval 19350	. . . . 5 ⊢ ((𝑇 ∈ (SubGrp‘𝐺) ∧ 𝑈 ∈ (SubGrp‘𝐺)) → (𝑥 ∈ (𝑇 ⊕ 𝑈) ↔ ∃𝑎 ∈ 𝑇 ∃𝑏 ∈ 𝑈 𝑥 = (𝑎(+g‘𝐺)𝑏)))
14	13	3adant3 1132	. . . 4 ⊢ ((𝑇 ∈ (SubGrp‘𝐺) ∧ 𝑈 ∈ (SubGrp‘𝐺) ∧ 𝑇 ⊆ (𝑍‘𝑈)) → (𝑥 ∈ (𝑇 ⊕ 𝑈) ↔ ∃𝑎 ∈ 𝑇 ∃𝑏 ∈ 𝑈 𝑥 = (𝑎(+g‘𝐺)𝑏)))
15	1	adantr 482	. . . . . . . . . 10 ⊢ (((𝑇 ∈ (SubGrp‘𝐺) ∧ 𝑈 ∈ (SubGrp‘𝐺) ∧ 𝑇 ⊆ (𝑍‘𝑈)) ∧ (𝑎 ∈ 𝑇 ∧ 𝑏 ∈ 𝑈)) → 𝑇 ∈ (SubGrp‘𝐺))
16		subgrcl 18856	. . . . . . . . . 10 ⊢ (𝑇 ∈ (SubGrp‘𝐺) → 𝐺 ∈ Grp)
17	15, 16	syl 17	. . . . . . . . 9 ⊢ (((𝑇 ∈ (SubGrp‘𝐺) ∧ 𝑈 ∈ (SubGrp‘𝐺) ∧ 𝑇 ⊆ (𝑍‘𝑈)) ∧ (𝑎 ∈ 𝑇 ∧ 𝑏 ∈ 𝑈)) → 𝐺 ∈ Grp)
18		eqid 2737	. . . . . . . . . . . 12 ⊢ (Base‘𝐺) = (Base‘𝐺)
19	18	subgss 18852	. . . . . . . . . . 11 ⊢ (𝑇 ∈ (SubGrp‘𝐺) → 𝑇 ⊆ (Base‘𝐺))
20	15, 19	syl 17	. . . . . . . . . 10 ⊢ (((𝑇 ∈ (SubGrp‘𝐺) ∧ 𝑈 ∈ (SubGrp‘𝐺) ∧ 𝑇 ⊆ (𝑍‘𝑈)) ∧ (𝑎 ∈ 𝑇 ∧ 𝑏 ∈ 𝑈)) → 𝑇 ⊆ (Base‘𝐺))
21		simprl 769	. . . . . . . . . 10 ⊢ (((𝑇 ∈ (SubGrp‘𝐺) ∧ 𝑈 ∈ (SubGrp‘𝐺) ∧ 𝑇 ⊆ (𝑍‘𝑈)) ∧ (𝑎 ∈ 𝑇 ∧ 𝑏 ∈ 𝑈)) → 𝑎 ∈ 𝑇)
22	20, 21	sseldd 3936	. . . . . . . . 9 ⊢ (((𝑇 ∈ (SubGrp‘𝐺) ∧ 𝑈 ∈ (SubGrp‘𝐺) ∧ 𝑇 ⊆ (𝑍‘𝑈)) ∧ (𝑎 ∈ 𝑇 ∧ 𝑏 ∈ 𝑈)) → 𝑎 ∈ (Base‘𝐺))
23	4	adantr 482	. . . . . . . . . . 11 ⊢ (((𝑇 ∈ (SubGrp‘𝐺) ∧ 𝑈 ∈ (SubGrp‘𝐺) ∧ 𝑇 ⊆ (𝑍‘𝑈)) ∧ (𝑎 ∈ 𝑇 ∧ 𝑏 ∈ 𝑈)) → 𝑈 ∈ (SubGrp‘𝐺))
24	18	subgss 18852	. . . . . . . . . . 11 ⊢ (𝑈 ∈ (SubGrp‘𝐺) → 𝑈 ⊆ (Base‘𝐺))
25	23, 24	syl 17	. . . . . . . . . 10 ⊢ (((𝑇 ∈ (SubGrp‘𝐺) ∧ 𝑈 ∈ (SubGrp‘𝐺) ∧ 𝑇 ⊆ (𝑍‘𝑈)) ∧ (𝑎 ∈ 𝑇 ∧ 𝑏 ∈ 𝑈)) → 𝑈 ⊆ (Base‘𝐺))
26		simprr 771	. . . . . . . . . 10 ⊢ (((𝑇 ∈ (SubGrp‘𝐺) ∧ 𝑈 ∈ (SubGrp‘𝐺) ∧ 𝑇 ⊆ (𝑍‘𝑈)) ∧ (𝑎 ∈ 𝑇 ∧ 𝑏 ∈ 𝑈)) → 𝑏 ∈ 𝑈)
27	25, 26	sseldd 3936	. . . . . . . . 9 ⊢ (((𝑇 ∈ (SubGrp‘𝐺) ∧ 𝑈 ∈ (SubGrp‘𝐺) ∧ 𝑇 ⊆ (𝑍‘𝑈)) ∧ (𝑎 ∈ 𝑇 ∧ 𝑏 ∈ 𝑈)) → 𝑏 ∈ (Base‘𝐺))
28		eqid 2737	. . . . . . . . . 10 ⊢ (invg‘𝐺) = (invg‘𝐺)
29	18, 12, 28	grpinvadd 18749	. . . . . . . . 9 ⊢ ((𝐺 ∈ Grp ∧ 𝑎 ∈ (Base‘𝐺) ∧ 𝑏 ∈ (Base‘𝐺)) → ((invg‘𝐺)‘(𝑎(+g‘𝐺)𝑏)) = (((invg‘𝐺)‘𝑏)(+g‘𝐺)((invg‘𝐺)‘𝑎)))
30	17, 22, 27, 29	syl3anc 1371	. . . . . . . 8 ⊢ (((𝑇 ∈ (SubGrp‘𝐺) ∧ 𝑈 ∈ (SubGrp‘𝐺) ∧ 𝑇 ⊆ (𝑍‘𝑈)) ∧ (𝑎 ∈ 𝑇 ∧ 𝑏 ∈ 𝑈)) → ((invg‘𝐺)‘(𝑎(+g‘𝐺)𝑏)) = (((invg‘𝐺)‘𝑏)(+g‘𝐺)((invg‘𝐺)‘𝑎)))
31	7	adantr 482	. . . . . . . . . 10 ⊢ (((𝑇 ∈ (SubGrp‘𝐺) ∧ 𝑈 ∈ (SubGrp‘𝐺) ∧ 𝑇 ⊆ (𝑍‘𝑈)) ∧ (𝑎 ∈ 𝑇 ∧ 𝑏 ∈ 𝑈)) → 𝑇 ⊆ (𝑍‘𝑈))
32	28	subginvcl 18860	. . . . . . . . . . 11 ⊢ ((𝑇 ∈ (SubGrp‘𝐺) ∧ 𝑎 ∈ 𝑇) → ((invg‘𝐺)‘𝑎) ∈ 𝑇)
33	15, 21, 32	syl2anc 585	. . . . . . . . . 10 ⊢ (((𝑇 ∈ (SubGrp‘𝐺) ∧ 𝑈 ∈ (SubGrp‘𝐺) ∧ 𝑇 ⊆ (𝑍‘𝑈)) ∧ (𝑎 ∈ 𝑇 ∧ 𝑏 ∈ 𝑈)) → ((invg‘𝐺)‘𝑎) ∈ 𝑇)
34	31, 33	sseldd 3936	. . . . . . . . 9 ⊢ (((𝑇 ∈ (SubGrp‘𝐺) ∧ 𝑈 ∈ (SubGrp‘𝐺) ∧ 𝑇 ⊆ (𝑍‘𝑈)) ∧ (𝑎 ∈ 𝑇 ∧ 𝑏 ∈ 𝑈)) → ((invg‘𝐺)‘𝑎) ∈ (𝑍‘𝑈))
35	28	subginvcl 18860	. . . . . . . . . 10 ⊢ ((𝑈 ∈ (SubGrp‘𝐺) ∧ 𝑏 ∈ 𝑈) → ((invg‘𝐺)‘𝑏) ∈ 𝑈)
36	23, 26, 35	syl2anc 585	. . . . . . . . 9 ⊢ (((𝑇 ∈ (SubGrp‘𝐺) ∧ 𝑈 ∈ (SubGrp‘𝐺) ∧ 𝑇 ⊆ (𝑍‘𝑈)) ∧ (𝑎 ∈ 𝑇 ∧ 𝑏 ∈ 𝑈)) → ((invg‘𝐺)‘𝑏) ∈ 𝑈)
37	12, 9	cntzi 19031	. . . . . . . . 9 ⊢ ((((invg‘𝐺)‘𝑎) ∈ (𝑍‘𝑈) ∧ ((invg‘𝐺)‘𝑏) ∈ 𝑈) → (((invg‘𝐺)‘𝑎)(+g‘𝐺)((invg‘𝐺)‘𝑏)) = (((invg‘𝐺)‘𝑏)(+g‘𝐺)((invg‘𝐺)‘𝑎)))
38	34, 36, 37	syl2anc 585	. . . . . . . 8 ⊢ (((𝑇 ∈ (SubGrp‘𝐺) ∧ 𝑈 ∈ (SubGrp‘𝐺) ∧ 𝑇 ⊆ (𝑍‘𝑈)) ∧ (𝑎 ∈ 𝑇 ∧ 𝑏 ∈ 𝑈)) → (((invg‘𝐺)‘𝑎)(+g‘𝐺)((invg‘𝐺)‘𝑏)) = (((invg‘𝐺)‘𝑏)(+g‘𝐺)((invg‘𝐺)‘𝑎)))
39	30, 38	eqtr4d 2780	. . . . . . 7 ⊢ (((𝑇 ∈ (SubGrp‘𝐺) ∧ 𝑈 ∈ (SubGrp‘𝐺) ∧ 𝑇 ⊆ (𝑍‘𝑈)) ∧ (𝑎 ∈ 𝑇 ∧ 𝑏 ∈ 𝑈)) → ((invg‘𝐺)‘(𝑎(+g‘𝐺)𝑏)) = (((invg‘𝐺)‘𝑎)(+g‘𝐺)((invg‘𝐺)‘𝑏)))
40	12, 8	lsmelvali 19351	. . . . . . . 8 ⊢ (((𝑇 ∈ (SubGrp‘𝐺) ∧ 𝑈 ∈ (SubGrp‘𝐺)) ∧ (((invg‘𝐺)‘𝑎) ∈ 𝑇 ∧ ((invg‘𝐺)‘𝑏) ∈ 𝑈)) → (((invg‘𝐺)‘𝑎)(+g‘𝐺)((invg‘𝐺)‘𝑏)) ∈ (𝑇 ⊕ 𝑈))
41	15, 23, 33, 36, 40	syl22anc 837	. . . . . . 7 ⊢ (((𝑇 ∈ (SubGrp‘𝐺) ∧ 𝑈 ∈ (SubGrp‘𝐺) ∧ 𝑇 ⊆ (𝑍‘𝑈)) ∧ (𝑎 ∈ 𝑇 ∧ 𝑏 ∈ 𝑈)) → (((invg‘𝐺)‘𝑎)(+g‘𝐺)((invg‘𝐺)‘𝑏)) ∈ (𝑇 ⊕ 𝑈))
42	39, 41	eqeltrd 2838	. . . . . 6 ⊢ (((𝑇 ∈ (SubGrp‘𝐺) ∧ 𝑈 ∈ (SubGrp‘𝐺) ∧ 𝑇 ⊆ (𝑍‘𝑈)) ∧ (𝑎 ∈ 𝑇 ∧ 𝑏 ∈ 𝑈)) → ((invg‘𝐺)‘(𝑎(+g‘𝐺)𝑏)) ∈ (𝑇 ⊕ 𝑈))
43		fveq2 6829	. . . . . . 7 ⊢ (𝑥 = (𝑎(+g‘𝐺)𝑏) → ((invg‘𝐺)‘𝑥) = ((invg‘𝐺)‘(𝑎(+g‘𝐺)𝑏)))
44	43	eleq1d 2822	. . . . . 6 ⊢ (𝑥 = (𝑎(+g‘𝐺)𝑏) → (((invg‘𝐺)‘𝑥) ∈ (𝑇 ⊕ 𝑈) ↔ ((invg‘𝐺)‘(𝑎(+g‘𝐺)𝑏)) ∈ (𝑇 ⊕ 𝑈)))
45	42, 44	syl5ibrcom 247	. . . . 5 ⊢ (((𝑇 ∈ (SubGrp‘𝐺) ∧ 𝑈 ∈ (SubGrp‘𝐺) ∧ 𝑇 ⊆ (𝑍‘𝑈)) ∧ (𝑎 ∈ 𝑇 ∧ 𝑏 ∈ 𝑈)) → (𝑥 = (𝑎(+g‘𝐺)𝑏) → ((invg‘𝐺)‘𝑥) ∈ (𝑇 ⊕ 𝑈)))
46	45	rexlimdvva 3202	. . . 4 ⊢ ((𝑇 ∈ (SubGrp‘𝐺) ∧ 𝑈 ∈ (SubGrp‘𝐺) ∧ 𝑇 ⊆ (𝑍‘𝑈)) → (∃𝑎 ∈ 𝑇 ∃𝑏 ∈ 𝑈 𝑥 = (𝑎(+g‘𝐺)𝑏) → ((invg‘𝐺)‘𝑥) ∈ (𝑇 ⊕ 𝑈)))
47	14, 46	sylbid 239	. . 3 ⊢ ((𝑇 ∈ (SubGrp‘𝐺) ∧ 𝑈 ∈ (SubGrp‘𝐺) ∧ 𝑇 ⊆ (𝑍‘𝑈)) → (𝑥 ∈ (𝑇 ⊕ 𝑈) → ((invg‘𝐺)‘𝑥) ∈ (𝑇 ⊕ 𝑈)))
48	47	ralrimiv 3139	. 2 ⊢ ((𝑇 ∈ (SubGrp‘𝐺) ∧ 𝑈 ∈ (SubGrp‘𝐺) ∧ 𝑇 ⊆ (𝑍‘𝑈)) → ∀𝑥 ∈ (𝑇 ⊕ 𝑈)((invg‘𝐺)‘𝑥) ∈ (𝑇 ⊕ 𝑈))
49	1, 16	syl 17	. . 3 ⊢ ((𝑇 ∈ (SubGrp‘𝐺) ∧ 𝑈 ∈ (SubGrp‘𝐺) ∧ 𝑇 ⊆ (𝑍‘𝑈)) → 𝐺 ∈ Grp)
50	28	issubg3 18869	. . 3 ⊢ (𝐺 ∈ Grp → ((𝑇 ⊕ 𝑈) ∈ (SubGrp‘𝐺) ↔ ((𝑇 ⊕ 𝑈) ∈ (SubMnd‘𝐺) ∧ ∀𝑥 ∈ (𝑇 ⊕ 𝑈)((invg‘𝐺)‘𝑥) ∈ (𝑇 ⊕ 𝑈))))
51	49, 50	syl 17	. 2 ⊢ ((𝑇 ∈ (SubGrp‘𝐺) ∧ 𝑈 ∈ (SubGrp‘𝐺) ∧ 𝑇 ⊆ (𝑍‘𝑈)) → ((𝑇 ⊕ 𝑈) ∈ (SubGrp‘𝐺) ↔ ((𝑇 ⊕ 𝑈) ∈ (SubMnd‘𝐺) ∧ ∀𝑥 ∈ (𝑇 ⊕ 𝑈)((invg‘𝐺)‘𝑥) ∈ (𝑇 ⊕ 𝑈))))
52	11, 48, 51	mpbir2and 711	1 ⊢ ((𝑇 ∈ (SubGrp‘𝐺) ∧ 𝑈 ∈ (SubGrp‘𝐺) ∧ 𝑇 ⊆ (𝑍‘𝑈)) → (𝑇 ⊕ 𝑈) ∈ (SubGrp‘𝐺))

Syntax hints:   → wi 4   ↔ wb 205   ∧ wa 397   ∧ w3a 1087   = wceq 1541   ∈ wcel 2106  ∀wral 3062  ∃wrex 3071   ⊆ wss 3901  ‘cfv 6483  (class class class)co 7341  Basecbs 17009  +_gcplusg 17059  SubMndcsubmnd 18526  Grpcgrp 18673  inv_gcminusg 18674  SubGrpcsubg 18845  Cntzccntz 19017  LSSumclsm 19335

This theorem was proved from axioms:  ax-mp 5  ax-1 6  ax-2 7  ax-3 8  ax-gen 1797  ax-4 1811  ax-5 1913  ax-6 1971  ax-7 2011  ax-8 2108  ax-9 2116  ax-10 2137  ax-11 2154  ax-12 2171  ax-ext 2708  ax-rep 5233  ax-sep 5247  ax-nul 5254  ax-pow 5312  ax-pr 5376  ax-un 7654  ax-cnex 11032  ax-resscn 11033  ax-1cn 11034  ax-icn 11035  ax-addcl 11036  ax-addrcl 11037  ax-mulcl 11038  ax-mulrcl 11039  ax-mulcom 11040  ax-addass 11041  ax-mulass 11042  ax-distr 11043  ax-i2m1 11044  ax-1ne0 11045  ax-1rid 11046  ax-rnegex 11047  ax-rrecex 11048  ax-cnre 11049  ax-pre-lttri 11050  ax-pre-lttrn 11051  ax-pre-ltadd 11052  ax-pre-mulgt0 11053

This theorem depends on definitions:  df-bi 206  df-an 398  df-or 846  df-3or 1088  df-3an 1089  df-tru 1544  df-fal 1554  df-ex 1782  df-nf 1786  df-sb 2068  df-mo 2539  df-eu 2568  df-clab 2715  df-cleq 2729  df-clel 2815  df-nfc 2887  df-ne 2942  df-nel 3048  df-ral 3063  df-rex 3072  df-rmo 3350  df-reu 3351  df-rab 3405  df-v 3444  df-sbc 3731  df-csb 3847  df-dif 3904  df-un 3906  df-in 3908  df-ss 3918  df-pss 3920  df-nul 4274  df-if 4478  df-pw 4553  df-sn 4578  df-pr 4580  df-op 4584  df-uni 4857  df-iun 4947  df-br 5097  df-opab 5159  df-mpt 5180  df-tr 5214  df-id 5522  df-eprel 5528  df-po 5536  df-so 5537  df-fr 5579  df-we 5581  df-xp 5630  df-rel 5631  df-cnv 5632  df-co 5633  df-dm 5634  df-rn 5635  df-res 5636  df-ima 5637  df-pred 6242  df-ord 6309  df-on 6310  df-lim 6311  df-suc 6312  df-iota 6435  df-fun 6485  df-fn 6486  df-f 6487  df-f1 6488  df-fo 6489  df-f1o 6490  df-fv 6491  df-riota 7297  df-ov 7344  df-oprab 7345  df-mpo 7346  df-om 7785  df-1st 7903  df-2nd 7904  df-frecs 8171  df-wrecs 8202  df-recs 8276  df-rdg 8315  df-er 8573  df-en 8809  df-dom 8810  df-sdom 8811  df-pnf 11116  df-mnf 11117  df-xr 11118  df-ltxr 11119  df-le 11120  df-sub 11312  df-neg 11313  df-nn 12079  df-2 12141  df-sets 16962  df-slot 16980  df-ndx 16992  df-base 17010  df-ress 17039  df-plusg 17072  df-0g 17249  df-mgm 18423  df-sgrp 18472  df-mnd 18483  df-submnd 18528  df-grp 18676  df-minusg 18677  df-subg 18848  df-cntz 19019  df-lsm 19337

This theorem is referenced by:  pj1ghm  19404  lsmsubg2  19555  dprd2da  19739  dmdprdsplit2lem  19742  dprdsplit  19745