Theorem grpissubg 17614

Description: If the base set of a group is contained in the base set of another group, and the group operation of the group is the restriction of the group operation of the other group to its base set, then the (base set of the) group is subgroup of the other group. (Contributed by AV, 14-Mar-2019.)

Hypotheses

Ref	Expression
grpissubg.b	⊢ 𝐵 = (Base‘𝐺)
grpissubg.s	⊢ 𝑆 = (Base‘𝐻)

Assertion

Ref	Expression
grpissubg	⊢ ((𝐺 ∈ Grp ∧ 𝐻 ∈ Grp) → ((𝑆 ⊆ 𝐵 ∧ (+g‘𝐻) = ((+g‘𝐺) ↾ (𝑆 × 𝑆))) → 𝑆 ∈ (SubGrp‘𝐺)))

Proof of Theorem grpissubg

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

Step	Hyp	Ref	Expression
1		simpl 473	. . . 4 ⊢ ((𝑆 ⊆ 𝐵 ∧ (+g‘𝐻) = ((+g‘𝐺) ↾ (𝑆 × 𝑆))) → 𝑆 ⊆ 𝐵)
2	1	adantl 482	. . 3 ⊢ (((𝐺 ∈ Grp ∧ 𝐻 ∈ Grp) ∧ (𝑆 ⊆ 𝐵 ∧ (+g‘𝐻) = ((+g‘𝐺) ↾ (𝑆 × 𝑆)))) → 𝑆 ⊆ 𝐵)
3		grpissubg.s	. . . . 5 ⊢ 𝑆 = (Base‘𝐻)
4	3	grpbn0 17451	. . . 4 ⊢ (𝐻 ∈ Grp → 𝑆 ≠ ∅)
5	4	ad2antlr 763	. . 3 ⊢ (((𝐺 ∈ Grp ∧ 𝐻 ∈ Grp) ∧ (𝑆 ⊆ 𝐵 ∧ (+g‘𝐻) = ((+g‘𝐺) ↾ (𝑆 × 𝑆)))) → 𝑆 ≠ ∅)
6		ovres 6800	. . . . . . . 8 ⊢ ((𝑎 ∈ 𝑆 ∧ 𝑏 ∈ 𝑆) → (𝑎((+g‘𝐺) ↾ (𝑆 × 𝑆))𝑏) = (𝑎(+g‘𝐺)𝑏))
7	6	adantll 750	. . . . . . 7 ⊢ (((((𝐺 ∈ Grp ∧ 𝐻 ∈ Grp) ∧ (𝑆 ⊆ 𝐵 ∧ (+g‘𝐻) = ((+g‘𝐺) ↾ (𝑆 × 𝑆)))) ∧ 𝑎 ∈ 𝑆) ∧ 𝑏 ∈ 𝑆) → (𝑎((+g‘𝐺) ↾ (𝑆 × 𝑆))𝑏) = (𝑎(+g‘𝐺)𝑏))
8		simplr 792	. . . . . . . . . 10 ⊢ (((𝐺 ∈ Grp ∧ 𝐻 ∈ Grp) ∧ (𝑆 ⊆ 𝐵 ∧ (+g‘𝐻) = ((+g‘𝐺) ↾ (𝑆 × 𝑆)))) → 𝐻 ∈ Grp)
9	8	ad2antrr 762	. . . . . . . . 9 ⊢ (((((𝐺 ∈ Grp ∧ 𝐻 ∈ Grp) ∧ (𝑆 ⊆ 𝐵 ∧ (+g‘𝐻) = ((+g‘𝐺) ↾ (𝑆 × 𝑆)))) ∧ 𝑎 ∈ 𝑆) ∧ 𝑏 ∈ 𝑆) → 𝐻 ∈ Grp)
10		simplr 792	. . . . . . . . 9 ⊢ (((((𝐺 ∈ Grp ∧ 𝐻 ∈ Grp) ∧ (𝑆 ⊆ 𝐵 ∧ (+g‘𝐻) = ((+g‘𝐺) ↾ (𝑆 × 𝑆)))) ∧ 𝑎 ∈ 𝑆) ∧ 𝑏 ∈ 𝑆) → 𝑎 ∈ 𝑆)
11		simpr 477	. . . . . . . . 9 ⊢ (((((𝐺 ∈ Grp ∧ 𝐻 ∈ Grp) ∧ (𝑆 ⊆ 𝐵 ∧ (+g‘𝐻) = ((+g‘𝐺) ↾ (𝑆 × 𝑆)))) ∧ 𝑎 ∈ 𝑆) ∧ 𝑏 ∈ 𝑆) → 𝑏 ∈ 𝑆)
12		eqid 2622	. . . . . . . . . 10 ⊢ (+g‘𝐻) = (+g‘𝐻)
13	3, 12	grpcl 17430	. . . . . . . . 9 ⊢ ((𝐻 ∈ Grp ∧ 𝑎 ∈ 𝑆 ∧ 𝑏 ∈ 𝑆) → (𝑎(+g‘𝐻)𝑏) ∈ 𝑆)
14	9, 10, 11, 13	syl3anc 1326	. . . . . . . 8 ⊢ (((((𝐺 ∈ Grp ∧ 𝐻 ∈ Grp) ∧ (𝑆 ⊆ 𝐵 ∧ (+g‘𝐻) = ((+g‘𝐺) ↾ (𝑆 × 𝑆)))) ∧ 𝑎 ∈ 𝑆) ∧ 𝑏 ∈ 𝑆) → (𝑎(+g‘𝐻)𝑏) ∈ 𝑆)
15		oveq 6656	. . . . . . . . . . . . 13 ⊢ ((+g‘𝐻) = ((+g‘𝐺) ↾ (𝑆 × 𝑆)) → (𝑎(+g‘𝐻)𝑏) = (𝑎((+g‘𝐺) ↾ (𝑆 × 𝑆))𝑏))
16	15	eqcomd 2628	. . . . . . . . . . . 12 ⊢ ((+g‘𝐻) = ((+g‘𝐺) ↾ (𝑆 × 𝑆)) → (𝑎((+g‘𝐺) ↾ (𝑆 × 𝑆))𝑏) = (𝑎(+g‘𝐻)𝑏))
17	16	eleq1d 2686	. . . . . . . . . . 11 ⊢ ((+g‘𝐻) = ((+g‘𝐺) ↾ (𝑆 × 𝑆)) → ((𝑎((+g‘𝐺) ↾ (𝑆 × 𝑆))𝑏) ∈ 𝑆 ↔ (𝑎(+g‘𝐻)𝑏) ∈ 𝑆))
18	17	adantl 482	. . . . . . . . . 10 ⊢ ((𝑆 ⊆ 𝐵 ∧ (+g‘𝐻) = ((+g‘𝐺) ↾ (𝑆 × 𝑆))) → ((𝑎((+g‘𝐺) ↾ (𝑆 × 𝑆))𝑏) ∈ 𝑆 ↔ (𝑎(+g‘𝐻)𝑏) ∈ 𝑆))
19	18	adantl 482	. . . . . . . . 9 ⊢ (((𝐺 ∈ Grp ∧ 𝐻 ∈ Grp) ∧ (𝑆 ⊆ 𝐵 ∧ (+g‘𝐻) = ((+g‘𝐺) ↾ (𝑆 × 𝑆)))) → ((𝑎((+g‘𝐺) ↾ (𝑆 × 𝑆))𝑏) ∈ 𝑆 ↔ (𝑎(+g‘𝐻)𝑏) ∈ 𝑆))
20	19	ad2antrr 762	. . . . . . . 8 ⊢ (((((𝐺 ∈ Grp ∧ 𝐻 ∈ Grp) ∧ (𝑆 ⊆ 𝐵 ∧ (+g‘𝐻) = ((+g‘𝐺) ↾ (𝑆 × 𝑆)))) ∧ 𝑎 ∈ 𝑆) ∧ 𝑏 ∈ 𝑆) → ((𝑎((+g‘𝐺) ↾ (𝑆 × 𝑆))𝑏) ∈ 𝑆 ↔ (𝑎(+g‘𝐻)𝑏) ∈ 𝑆))
21	14, 20	mpbird 247	. . . . . . 7 ⊢ (((((𝐺 ∈ Grp ∧ 𝐻 ∈ Grp) ∧ (𝑆 ⊆ 𝐵 ∧ (+g‘𝐻) = ((+g‘𝐺) ↾ (𝑆 × 𝑆)))) ∧ 𝑎 ∈ 𝑆) ∧ 𝑏 ∈ 𝑆) → (𝑎((+g‘𝐺) ↾ (𝑆 × 𝑆))𝑏) ∈ 𝑆)
22	7, 21	eqeltrrd 2702	. . . . . 6 ⊢ (((((𝐺 ∈ Grp ∧ 𝐻 ∈ Grp) ∧ (𝑆 ⊆ 𝐵 ∧ (+g‘𝐻) = ((+g‘𝐺) ↾ (𝑆 × 𝑆)))) ∧ 𝑎 ∈ 𝑆) ∧ 𝑏 ∈ 𝑆) → (𝑎(+g‘𝐺)𝑏) ∈ 𝑆)
23	22	ralrimiva 2966	. . . . 5 ⊢ ((((𝐺 ∈ Grp ∧ 𝐻 ∈ Grp) ∧ (𝑆 ⊆ 𝐵 ∧ (+g‘𝐻) = ((+g‘𝐺) ↾ (𝑆 × 𝑆)))) ∧ 𝑎 ∈ 𝑆) → ∀𝑏 ∈ 𝑆 (𝑎(+g‘𝐺)𝑏) ∈ 𝑆)
24		simpl 473	. . . . . . . . 9 ⊢ ((𝐺 ∈ Grp ∧ 𝐻 ∈ Grp) → 𝐺 ∈ Grp)
25	24	adantr 481	. . . . . . . 8 ⊢ (((𝐺 ∈ Grp ∧ 𝐻 ∈ Grp) ∧ (𝑆 ⊆ 𝐵 ∧ (+g‘𝐻) = ((+g‘𝐺) ↾ (𝑆 × 𝑆)))) → 𝐺 ∈ Grp)
26		grpissubg.b	. . . . . . . . . . . 12 ⊢ 𝐵 = (Base‘𝐺)
27	26	sseq2i 3630	. . . . . . . . . . 11 ⊢ (𝑆 ⊆ 𝐵 ↔ 𝑆 ⊆ (Base‘𝐺))
28	27	biimpi 206	. . . . . . . . . 10 ⊢ (𝑆 ⊆ 𝐵 → 𝑆 ⊆ (Base‘𝐺))
29	28	adantr 481	. . . . . . . . 9 ⊢ ((𝑆 ⊆ 𝐵 ∧ (+g‘𝐻) = ((+g‘𝐺) ↾ (𝑆 × 𝑆))) → 𝑆 ⊆ (Base‘𝐺))
30	29	adantl 482	. . . . . . . 8 ⊢ (((𝐺 ∈ Grp ∧ 𝐻 ∈ Grp) ∧ (𝑆 ⊆ 𝐵 ∧ (+g‘𝐻) = ((+g‘𝐺) ↾ (𝑆 × 𝑆)))) → 𝑆 ⊆ (Base‘𝐺))
31		ovres 6800	. . . . . . . . . . 11 ⊢ ((𝑥 ∈ 𝑆 ∧ 𝑦 ∈ 𝑆) → (𝑥((+g‘𝐺) ↾ (𝑆 × 𝑆))𝑦) = (𝑥(+g‘𝐺)𝑦))
32	31	adantl 482	. . . . . . . . . 10 ⊢ ((((𝐺 ∈ Grp ∧ 𝐻 ∈ Grp) ∧ (𝑆 ⊆ 𝐵 ∧ (+g‘𝐻) = ((+g‘𝐺) ↾ (𝑆 × 𝑆)))) ∧ (𝑥 ∈ 𝑆 ∧ 𝑦 ∈ 𝑆)) → (𝑥((+g‘𝐺) ↾ (𝑆 × 𝑆))𝑦) = (𝑥(+g‘𝐺)𝑦))
33		oveq 6656	. . . . . . . . . . . . 13 ⊢ ((+g‘𝐻) = ((+g‘𝐺) ↾ (𝑆 × 𝑆)) → (𝑥(+g‘𝐻)𝑦) = (𝑥((+g‘𝐺) ↾ (𝑆 × 𝑆))𝑦))
34	33	adantl 482	. . . . . . . . . . . 12 ⊢ ((𝑆 ⊆ 𝐵 ∧ (+g‘𝐻) = ((+g‘𝐺) ↾ (𝑆 × 𝑆))) → (𝑥(+g‘𝐻)𝑦) = (𝑥((+g‘𝐺) ↾ (𝑆 × 𝑆))𝑦))
35	34	eqcomd 2628	. . . . . . . . . . 11 ⊢ ((𝑆 ⊆ 𝐵 ∧ (+g‘𝐻) = ((+g‘𝐺) ↾ (𝑆 × 𝑆))) → (𝑥((+g‘𝐺) ↾ (𝑆 × 𝑆))𝑦) = (𝑥(+g‘𝐻)𝑦))
36	35	ad2antlr 763	. . . . . . . . . 10 ⊢ ((((𝐺 ∈ Grp ∧ 𝐻 ∈ Grp) ∧ (𝑆 ⊆ 𝐵 ∧ (+g‘𝐻) = ((+g‘𝐺) ↾ (𝑆 × 𝑆)))) ∧ (𝑥 ∈ 𝑆 ∧ 𝑦 ∈ 𝑆)) → (𝑥((+g‘𝐺) ↾ (𝑆 × 𝑆))𝑦) = (𝑥(+g‘𝐻)𝑦))
37	32, 36	eqtr3d 2658	. . . . . . . . 9 ⊢ ((((𝐺 ∈ Grp ∧ 𝐻 ∈ Grp) ∧ (𝑆 ⊆ 𝐵 ∧ (+g‘𝐻) = ((+g‘𝐺) ↾ (𝑆 × 𝑆)))) ∧ (𝑥 ∈ 𝑆 ∧ 𝑦 ∈ 𝑆)) → (𝑥(+g‘𝐺)𝑦) = (𝑥(+g‘𝐻)𝑦))
38	37	ralrimivva 2971	. . . . . . . 8 ⊢ (((𝐺 ∈ Grp ∧ 𝐻 ∈ Grp) ∧ (𝑆 ⊆ 𝐵 ∧ (+g‘𝐻) = ((+g‘𝐺) ↾ (𝑆 × 𝑆)))) → ∀𝑥 ∈ 𝑆 ∀𝑦 ∈ 𝑆 (𝑥(+g‘𝐺)𝑦) = (𝑥(+g‘𝐻)𝑦))
39	25, 8, 3, 30, 38	grpinvssd 17492	. . . . . . 7 ⊢ (((𝐺 ∈ Grp ∧ 𝐻 ∈ Grp) ∧ (𝑆 ⊆ 𝐵 ∧ (+g‘𝐻) = ((+g‘𝐺) ↾ (𝑆 × 𝑆)))) → (𝑎 ∈ 𝑆 → ((invg‘𝐻)‘𝑎) = ((invg‘𝐺)‘𝑎)))
40	39	imp 445	. . . . . 6 ⊢ ((((𝐺 ∈ Grp ∧ 𝐻 ∈ Grp) ∧ (𝑆 ⊆ 𝐵 ∧ (+g‘𝐻) = ((+g‘𝐺) ↾ (𝑆 × 𝑆)))) ∧ 𝑎 ∈ 𝑆) → ((invg‘𝐻)‘𝑎) = ((invg‘𝐺)‘𝑎))
41		eqid 2622	. . . . . . . . . 10 ⊢ (invg‘𝐻) = (invg‘𝐻)
42	3, 41	grpinvcl 17467	. . . . . . . . 9 ⊢ ((𝐻 ∈ Grp ∧ 𝑎 ∈ 𝑆) → ((invg‘𝐻)‘𝑎) ∈ 𝑆)
43	42	ex 450	. . . . . . . 8 ⊢ (𝐻 ∈ Grp → (𝑎 ∈ 𝑆 → ((invg‘𝐻)‘𝑎) ∈ 𝑆))
44	43	ad2antlr 763	. . . . . . 7 ⊢ (((𝐺 ∈ Grp ∧ 𝐻 ∈ Grp) ∧ (𝑆 ⊆ 𝐵 ∧ (+g‘𝐻) = ((+g‘𝐺) ↾ (𝑆 × 𝑆)))) → (𝑎 ∈ 𝑆 → ((invg‘𝐻)‘𝑎) ∈ 𝑆))
45	44	imp 445	. . . . . 6 ⊢ ((((𝐺 ∈ Grp ∧ 𝐻 ∈ Grp) ∧ (𝑆 ⊆ 𝐵 ∧ (+g‘𝐻) = ((+g‘𝐺) ↾ (𝑆 × 𝑆)))) ∧ 𝑎 ∈ 𝑆) → ((invg‘𝐻)‘𝑎) ∈ 𝑆)
46	40, 45	eqeltrrd 2702	. . . . 5 ⊢ ((((𝐺 ∈ Grp ∧ 𝐻 ∈ Grp) ∧ (𝑆 ⊆ 𝐵 ∧ (+g‘𝐻) = ((+g‘𝐺) ↾ (𝑆 × 𝑆)))) ∧ 𝑎 ∈ 𝑆) → ((invg‘𝐺)‘𝑎) ∈ 𝑆)
47	23, 46	jca 554	. . . 4 ⊢ ((((𝐺 ∈ Grp ∧ 𝐻 ∈ Grp) ∧ (𝑆 ⊆ 𝐵 ∧ (+g‘𝐻) = ((+g‘𝐺) ↾ (𝑆 × 𝑆)))) ∧ 𝑎 ∈ 𝑆) → (∀𝑏 ∈ 𝑆 (𝑎(+g‘𝐺)𝑏) ∈ 𝑆 ∧ ((invg‘𝐺)‘𝑎) ∈ 𝑆))
48	47	ralrimiva 2966	. . 3 ⊢ (((𝐺 ∈ Grp ∧ 𝐻 ∈ Grp) ∧ (𝑆 ⊆ 𝐵 ∧ (+g‘𝐻) = ((+g‘𝐺) ↾ (𝑆 × 𝑆)))) → ∀𝑎 ∈ 𝑆 (∀𝑏 ∈ 𝑆 (𝑎(+g‘𝐺)𝑏) ∈ 𝑆 ∧ ((invg‘𝐺)‘𝑎) ∈ 𝑆))
49		eqid 2622	. . . . 5 ⊢ (+g‘𝐺) = (+g‘𝐺)
50		eqid 2622	. . . . 5 ⊢ (invg‘𝐺) = (invg‘𝐺)
51	26, 49, 50	issubg2 17609	. . . 4 ⊢ (𝐺 ∈ Grp → (𝑆 ∈ (SubGrp‘𝐺) ↔ (𝑆 ⊆ 𝐵 ∧ 𝑆 ≠ ∅ ∧ ∀𝑎 ∈ 𝑆 (∀𝑏 ∈ 𝑆 (𝑎(+g‘𝐺)𝑏) ∈ 𝑆 ∧ ((invg‘𝐺)‘𝑎) ∈ 𝑆))))
52	51	ad2antrr 762	. . 3 ⊢ (((𝐺 ∈ Grp ∧ 𝐻 ∈ Grp) ∧ (𝑆 ⊆ 𝐵 ∧ (+g‘𝐻) = ((+g‘𝐺) ↾ (𝑆 × 𝑆)))) → (𝑆 ∈ (SubGrp‘𝐺) ↔ (𝑆 ⊆ 𝐵 ∧ 𝑆 ≠ ∅ ∧ ∀𝑎 ∈ 𝑆 (∀𝑏 ∈ 𝑆 (𝑎(+g‘𝐺)𝑏) ∈ 𝑆 ∧ ((invg‘𝐺)‘𝑎) ∈ 𝑆))))
53	2, 5, 48, 52	mpbir3and 1245	. 2 ⊢ (((𝐺 ∈ Grp ∧ 𝐻 ∈ Grp) ∧ (𝑆 ⊆ 𝐵 ∧ (+g‘𝐻) = ((+g‘𝐺) ↾ (𝑆 × 𝑆)))) → 𝑆 ∈ (SubGrp‘𝐺))
54	53	ex 450	1 ⊢ ((𝐺 ∈ Grp ∧ 𝐻 ∈ Grp) → ((𝑆 ⊆ 𝐵 ∧ (+g‘𝐻) = ((+g‘𝐺) ↾ (𝑆 × 𝑆))) → 𝑆 ∈ (SubGrp‘𝐺)))

Syntax hints:   → wi 4   ↔ wb 196   ∧ wa 384   ∧ w3a 1037   = wceq 1483   ∈ wcel 1990   ≠ wne 2794  ∀wral 2912   ⊆ wss 3574  ∅c0 3915   × cxp 5112   ↾ cres 5116  ‘cfv 5888  (class class class)co 6650  Basecbs 15857  +_gcplusg 15941  Grpcgrp 17422  inv_gcminusg 17423  SubGrpcsubg 17588

This theorem was proved from axioms:  ax-mp 5  ax-1 6  ax-2 7  ax-3 8  ax-gen 1722  ax-4 1737  ax-5 1839  ax-6 1888  ax-7 1935  ax-8 1992  ax-9 1999  ax-10 2019  ax-11 2034  ax-12 2047  ax-13 2246  ax-ext 2602  ax-rep 4771  ax-sep 4781  ax-nul 4789  ax-pow 4843  ax-pr 4906  ax-un 6949  ax-cnex 9992  ax-resscn 9993  ax-1cn 9994  ax-icn 9995  ax-addcl 9996  ax-addrcl 9997  ax-mulcl 9998  ax-mulrcl 9999  ax-mulcom 10000  ax-addass 10001  ax-mulass 10002  ax-distr 10003  ax-i2m1 10004  ax-1ne0 10005  ax-1rid 10006  ax-rnegex 10007  ax-rrecex 10008  ax-cnre 10009  ax-pre-lttri 10010  ax-pre-lttrn 10011  ax-pre-ltadd 10012  ax-pre-mulgt0 10013

This theorem depends on definitions:  df-bi 197  df-or 385  df-an 386  df-3or 1038  df-3an 1039  df-tru 1486  df-ex 1705  df-nf 1710  df-sb 1881  df-eu 2474  df-mo 2475  df-clab 2609  df-cleq 2615  df-clel 2618  df-nfc 2753  df-ne 2795  df-nel 2898  df-ral 2917  df-rex 2918  df-reu 2919  df-rmo 2920  df-rab 2921  df-v 3202  df-sbc 3436  df-csb 3534  df-dif 3577  df-un 3579  df-in 3581  df-ss 3588  df-pss 3590  df-nul 3916  df-if 4087  df-pw 4160  df-sn 4178  df-pr 4180  df-tp 4182  df-op 4184  df-uni 4437  df-iun 4522  df-br 4654  df-opab 4713  df-mpt 4730  df-tr 4753  df-id 5024  df-eprel 5029  df-po 5035  df-so 5036  df-fr 5073  df-we 5075  df-xp 5120  df-rel 5121  df-cnv 5122  df-co 5123  df-dm 5124  df-rn 5125  df-res 5126  df-ima 5127  df-pred 5680  df-ord 5726  df-on 5727  df-lim 5728  df-suc 5729  df-iota 5851  df-fun 5890  df-fn 5891  df-f 5892  df-f1 5893  df-fo 5894  df-f1o 5895  df-fv 5896  df-riota 6611  df-ov 6653  df-oprab 6654  df-mpt2 6655  df-om 7066  df-wrecs 7407  df-recs 7468  df-rdg 7506  df-er 7742  df-en 7956  df-dom 7957  df-sdom 7958  df-pnf 10076  df-mnf 10077  df-xr 10078  df-ltxr 10079  df-le 10080  df-sub 10268  df-neg 10269  df-nn 11021  df-2 11079  df-ndx 15860  df-slot 15861  df-base 15863  df-sets 15864  df-ress 15865  df-plusg 15954  df-0g 16102  df-mgm 17242  df-sgrp 17284  df-mnd 17295  df-grp 17425  df-minusg 17426  df-subg 17591

This theorem is referenced by:  resgrpisgrp  17615  pgrpsubgsymg  17828