Theorem ghmf1 18379

Description: Two ways of saying a group homomorphism is 1-1 into its codomain. (Contributed by Paul Chapman, 3-Mar-2008.) (Revised by Mario Carneiro, 13-Jan-2015.)

Hypotheses

Ref	Expression
ghmf1.x	⊢ 𝑋 = (Base‘𝑆)
ghmf1.y	⊢ 𝑌 = (Base‘𝑇)
ghmf1.z	⊢ 0 = (0g‘𝑆)
ghmf1.u	⊢ 𝑈 = (0g‘𝑇)

Assertion

Ref	Expression
ghmf1	⊢ (𝐹 ∈ (𝑆 GrpHom 𝑇) → (𝐹:𝑋–1-1→𝑌 ↔ ∀𝑥 ∈ 𝑋 ((𝐹‘𝑥) = 𝑈 → 𝑥 = 0 )))

Distinct variable groups:   𝑥,𝐹   𝑥,𝑆   𝑥,𝑇   𝑥,𝑈   𝑥,𝑋   𝑥,𝑌   𝑥, 0

Proof of Theorem ghmf1

Dummy variables 𝑦 𝑧 are mutually distinct and distinct from all other variables.

Step	Hyp	Ref	Expression
1		ghmf1.z	. . . . . . . 8 ⊢ 0 = (0g‘𝑆)
2		ghmf1.u	. . . . . . . 8 ⊢ 𝑈 = (0g‘𝑇)
3	1, 2	ghmid 18356	. . . . . . 7 ⊢ (𝐹 ∈ (𝑆 GrpHom 𝑇) → (𝐹‘ 0 ) = 𝑈)
4	3	ad2antrr 725	. . . . . 6 ⊢ (((𝐹 ∈ (𝑆 GrpHom 𝑇) ∧ 𝐹:𝑋–1-1→𝑌) ∧ 𝑥 ∈ 𝑋) → (𝐹‘ 0 ) = 𝑈)
5	4	eqeq2d 2809	. . . . 5 ⊢ (((𝐹 ∈ (𝑆 GrpHom 𝑇) ∧ 𝐹:𝑋–1-1→𝑌) ∧ 𝑥 ∈ 𝑋) → ((𝐹‘𝑥) = (𝐹‘ 0 ) ↔ (𝐹‘𝑥) = 𝑈))
6		simplr 768	. . . . . 6 ⊢ (((𝐹 ∈ (𝑆 GrpHom 𝑇) ∧ 𝐹:𝑋–1-1→𝑌) ∧ 𝑥 ∈ 𝑋) → 𝐹:𝑋–1-1→𝑌)
7		simpr 488	. . . . . 6 ⊢ (((𝐹 ∈ (𝑆 GrpHom 𝑇) ∧ 𝐹:𝑋–1-1→𝑌) ∧ 𝑥 ∈ 𝑋) → 𝑥 ∈ 𝑋)
8		ghmgrp1 18352	. . . . . . . 8 ⊢ (𝐹 ∈ (𝑆 GrpHom 𝑇) → 𝑆 ∈ Grp)
9	8	ad2antrr 725	. . . . . . 7 ⊢ (((𝐹 ∈ (𝑆 GrpHom 𝑇) ∧ 𝐹:𝑋–1-1→𝑌) ∧ 𝑥 ∈ 𝑋) → 𝑆 ∈ Grp)
10		ghmf1.x	. . . . . . . 8 ⊢ 𝑋 = (Base‘𝑆)
11	10, 1	grpidcl 18123	. . . . . . 7 ⊢ (𝑆 ∈ Grp → 0 ∈ 𝑋)
12	9, 11	syl 17	. . . . . 6 ⊢ (((𝐹 ∈ (𝑆 GrpHom 𝑇) ∧ 𝐹:𝑋–1-1→𝑌) ∧ 𝑥 ∈ 𝑋) → 0 ∈ 𝑋)
13		f1fveq 6998	. . . . . 6 ⊢ ((𝐹:𝑋–1-1→𝑌 ∧ (𝑥 ∈ 𝑋 ∧ 0 ∈ 𝑋)) → ((𝐹‘𝑥) = (𝐹‘ 0 ) ↔ 𝑥 = 0 ))
14	6, 7, 12, 13	syl12anc 835	. . . . 5 ⊢ (((𝐹 ∈ (𝑆 GrpHom 𝑇) ∧ 𝐹:𝑋–1-1→𝑌) ∧ 𝑥 ∈ 𝑋) → ((𝐹‘𝑥) = (𝐹‘ 0 ) ↔ 𝑥 = 0 ))
15	5, 14	bitr3d 284	. . . 4 ⊢ (((𝐹 ∈ (𝑆 GrpHom 𝑇) ∧ 𝐹:𝑋–1-1→𝑌) ∧ 𝑥 ∈ 𝑋) → ((𝐹‘𝑥) = 𝑈 ↔ 𝑥 = 0 ))
16	15	biimpd 232	. . 3 ⊢ (((𝐹 ∈ (𝑆 GrpHom 𝑇) ∧ 𝐹:𝑋–1-1→𝑌) ∧ 𝑥 ∈ 𝑋) → ((𝐹‘𝑥) = 𝑈 → 𝑥 = 0 ))
17	16	ralrimiva 3149	. 2 ⊢ ((𝐹 ∈ (𝑆 GrpHom 𝑇) ∧ 𝐹:𝑋–1-1→𝑌) → ∀𝑥 ∈ 𝑋 ((𝐹‘𝑥) = 𝑈 → 𝑥 = 0 ))
18		ghmf1.y	. . . . 5 ⊢ 𝑌 = (Base‘𝑇)
19	10, 18	ghmf 18354	. . . 4 ⊢ (𝐹 ∈ (𝑆 GrpHom 𝑇) → 𝐹:𝑋⟶𝑌)
20	19	adantr 484	. . 3 ⊢ ((𝐹 ∈ (𝑆 GrpHom 𝑇) ∧ ∀𝑥 ∈ 𝑋 ((𝐹‘𝑥) = 𝑈 → 𝑥 = 0 )) → 𝐹:𝑋⟶𝑌)
21		eqid 2798	. . . . . . . . . 10 ⊢ (-g‘𝑆) = (-g‘𝑆)
22		eqid 2798	. . . . . . . . . 10 ⊢ (-g‘𝑇) = (-g‘𝑇)
23	10, 21, 22	ghmsub 18358	. . . . . . . . 9 ⊢ ((𝐹 ∈ (𝑆 GrpHom 𝑇) ∧ 𝑦 ∈ 𝑋 ∧ 𝑧 ∈ 𝑋) → (𝐹‘(𝑦(-g‘𝑆)𝑧)) = ((𝐹‘𝑦)(-g‘𝑇)(𝐹‘𝑧)))
24	23	3expb 1117	. . . . . . . 8 ⊢ ((𝐹 ∈ (𝑆 GrpHom 𝑇) ∧ (𝑦 ∈ 𝑋 ∧ 𝑧 ∈ 𝑋)) → (𝐹‘(𝑦(-g‘𝑆)𝑧)) = ((𝐹‘𝑦)(-g‘𝑇)(𝐹‘𝑧)))
25	24	adantlr 714	. . . . . . 7 ⊢ (((𝐹 ∈ (𝑆 GrpHom 𝑇) ∧ ∀𝑥 ∈ 𝑋 ((𝐹‘𝑥) = 𝑈 → 𝑥 = 0 )) ∧ (𝑦 ∈ 𝑋 ∧ 𝑧 ∈ 𝑋)) → (𝐹‘(𝑦(-g‘𝑆)𝑧)) = ((𝐹‘𝑦)(-g‘𝑇)(𝐹‘𝑧)))
26	25	eqeq1d 2800	. . . . . 6 ⊢ (((𝐹 ∈ (𝑆 GrpHom 𝑇) ∧ ∀𝑥 ∈ 𝑋 ((𝐹‘𝑥) = 𝑈 → 𝑥 = 0 )) ∧ (𝑦 ∈ 𝑋 ∧ 𝑧 ∈ 𝑋)) → ((𝐹‘(𝑦(-g‘𝑆)𝑧)) = 𝑈 ↔ ((𝐹‘𝑦)(-g‘𝑇)(𝐹‘𝑧)) = 𝑈))
27		fveqeq2 6654	. . . . . . . 8 ⊢ (𝑥 = (𝑦(-g‘𝑆)𝑧) → ((𝐹‘𝑥) = 𝑈 ↔ (𝐹‘(𝑦(-g‘𝑆)𝑧)) = 𝑈))
28		eqeq1 2802	. . . . . . . 8 ⊢ (𝑥 = (𝑦(-g‘𝑆)𝑧) → (𝑥 = 0 ↔ (𝑦(-g‘𝑆)𝑧) = 0 ))
29	27, 28	imbi12d 348	. . . . . . 7 ⊢ (𝑥 = (𝑦(-g‘𝑆)𝑧) → (((𝐹‘𝑥) = 𝑈 → 𝑥 = 0 ) ↔ ((𝐹‘(𝑦(-g‘𝑆)𝑧)) = 𝑈 → (𝑦(-g‘𝑆)𝑧) = 0 )))
30		simplr 768	. . . . . . 7 ⊢ (((𝐹 ∈ (𝑆 GrpHom 𝑇) ∧ ∀𝑥 ∈ 𝑋 ((𝐹‘𝑥) = 𝑈 → 𝑥 = 0 )) ∧ (𝑦 ∈ 𝑋 ∧ 𝑧 ∈ 𝑋)) → ∀𝑥 ∈ 𝑋 ((𝐹‘𝑥) = 𝑈 → 𝑥 = 0 ))
31	8	adantr 484	. . . . . . . 8 ⊢ ((𝐹 ∈ (𝑆 GrpHom 𝑇) ∧ ∀𝑥 ∈ 𝑋 ((𝐹‘𝑥) = 𝑈 → 𝑥 = 0 )) → 𝑆 ∈ Grp)
32	10, 21	grpsubcl 18171	. . . . . . . . 9 ⊢ ((𝑆 ∈ Grp ∧ 𝑦 ∈ 𝑋 ∧ 𝑧 ∈ 𝑋) → (𝑦(-g‘𝑆)𝑧) ∈ 𝑋)
33	32	3expb 1117	. . . . . . . 8 ⊢ ((𝑆 ∈ Grp ∧ (𝑦 ∈ 𝑋 ∧ 𝑧 ∈ 𝑋)) → (𝑦(-g‘𝑆)𝑧) ∈ 𝑋)
34	31, 33	sylan 583	. . . . . . 7 ⊢ (((𝐹 ∈ (𝑆 GrpHom 𝑇) ∧ ∀𝑥 ∈ 𝑋 ((𝐹‘𝑥) = 𝑈 → 𝑥 = 0 )) ∧ (𝑦 ∈ 𝑋 ∧ 𝑧 ∈ 𝑋)) → (𝑦(-g‘𝑆)𝑧) ∈ 𝑋)
35	29, 30, 34	rspcdva 3573	. . . . . 6 ⊢ (((𝐹 ∈ (𝑆 GrpHom 𝑇) ∧ ∀𝑥 ∈ 𝑋 ((𝐹‘𝑥) = 𝑈 → 𝑥 = 0 )) ∧ (𝑦 ∈ 𝑋 ∧ 𝑧 ∈ 𝑋)) → ((𝐹‘(𝑦(-g‘𝑆)𝑧)) = 𝑈 → (𝑦(-g‘𝑆)𝑧) = 0 ))
36	26, 35	sylbird 263	. . . . 5 ⊢ (((𝐹 ∈ (𝑆 GrpHom 𝑇) ∧ ∀𝑥 ∈ 𝑋 ((𝐹‘𝑥) = 𝑈 → 𝑥 = 0 )) ∧ (𝑦 ∈ 𝑋 ∧ 𝑧 ∈ 𝑋)) → (((𝐹‘𝑦)(-g‘𝑇)(𝐹‘𝑧)) = 𝑈 → (𝑦(-g‘𝑆)𝑧) = 0 ))
37		ghmgrp2 18353	. . . . . . 7 ⊢ (𝐹 ∈ (𝑆 GrpHom 𝑇) → 𝑇 ∈ Grp)
38	37	ad2antrr 725	. . . . . 6 ⊢ (((𝐹 ∈ (𝑆 GrpHom 𝑇) ∧ ∀𝑥 ∈ 𝑋 ((𝐹‘𝑥) = 𝑈 → 𝑥 = 0 )) ∧ (𝑦 ∈ 𝑋 ∧ 𝑧 ∈ 𝑋)) → 𝑇 ∈ Grp)
39	19	ad2antrr 725	. . . . . . 7 ⊢ (((𝐹 ∈ (𝑆 GrpHom 𝑇) ∧ ∀𝑥 ∈ 𝑋 ((𝐹‘𝑥) = 𝑈 → 𝑥 = 0 )) ∧ (𝑦 ∈ 𝑋 ∧ 𝑧 ∈ 𝑋)) → 𝐹:𝑋⟶𝑌)
40		simprl 770	. . . . . . 7 ⊢ (((𝐹 ∈ (𝑆 GrpHom 𝑇) ∧ ∀𝑥 ∈ 𝑋 ((𝐹‘𝑥) = 𝑈 → 𝑥 = 0 )) ∧ (𝑦 ∈ 𝑋 ∧ 𝑧 ∈ 𝑋)) → 𝑦 ∈ 𝑋)
41	39, 40	ffvelrnd 6829	. . . . . 6 ⊢ (((𝐹 ∈ (𝑆 GrpHom 𝑇) ∧ ∀𝑥 ∈ 𝑋 ((𝐹‘𝑥) = 𝑈 → 𝑥 = 0 )) ∧ (𝑦 ∈ 𝑋 ∧ 𝑧 ∈ 𝑋)) → (𝐹‘𝑦) ∈ 𝑌)
42		simprr 772	. . . . . . 7 ⊢ (((𝐹 ∈ (𝑆 GrpHom 𝑇) ∧ ∀𝑥 ∈ 𝑋 ((𝐹‘𝑥) = 𝑈 → 𝑥 = 0 )) ∧ (𝑦 ∈ 𝑋 ∧ 𝑧 ∈ 𝑋)) → 𝑧 ∈ 𝑋)
43	39, 42	ffvelrnd 6829	. . . . . 6 ⊢ (((𝐹 ∈ (𝑆 GrpHom 𝑇) ∧ ∀𝑥 ∈ 𝑋 ((𝐹‘𝑥) = 𝑈 → 𝑥 = 0 )) ∧ (𝑦 ∈ 𝑋 ∧ 𝑧 ∈ 𝑋)) → (𝐹‘𝑧) ∈ 𝑌)
44	18, 2, 22	grpsubeq0 18177	. . . . . 6 ⊢ ((𝑇 ∈ Grp ∧ (𝐹‘𝑦) ∈ 𝑌 ∧ (𝐹‘𝑧) ∈ 𝑌) → (((𝐹‘𝑦)(-g‘𝑇)(𝐹‘𝑧)) = 𝑈 ↔ (𝐹‘𝑦) = (𝐹‘𝑧)))
45	38, 41, 43, 44	syl3anc 1368	. . . . 5 ⊢ (((𝐹 ∈ (𝑆 GrpHom 𝑇) ∧ ∀𝑥 ∈ 𝑋 ((𝐹‘𝑥) = 𝑈 → 𝑥 = 0 )) ∧ (𝑦 ∈ 𝑋 ∧ 𝑧 ∈ 𝑋)) → (((𝐹‘𝑦)(-g‘𝑇)(𝐹‘𝑧)) = 𝑈 ↔ (𝐹‘𝑦) = (𝐹‘𝑧)))
46	8	ad2antrr 725	. . . . . 6 ⊢ (((𝐹 ∈ (𝑆 GrpHom 𝑇) ∧ ∀𝑥 ∈ 𝑋 ((𝐹‘𝑥) = 𝑈 → 𝑥 = 0 )) ∧ (𝑦 ∈ 𝑋 ∧ 𝑧 ∈ 𝑋)) → 𝑆 ∈ Grp)
47	10, 1, 21	grpsubeq0 18177	. . . . . 6 ⊢ ((𝑆 ∈ Grp ∧ 𝑦 ∈ 𝑋 ∧ 𝑧 ∈ 𝑋) → ((𝑦(-g‘𝑆)𝑧) = 0 ↔ 𝑦 = 𝑧))
48	46, 40, 42, 47	syl3anc 1368	. . . . 5 ⊢ (((𝐹 ∈ (𝑆 GrpHom 𝑇) ∧ ∀𝑥 ∈ 𝑋 ((𝐹‘𝑥) = 𝑈 → 𝑥 = 0 )) ∧ (𝑦 ∈ 𝑋 ∧ 𝑧 ∈ 𝑋)) → ((𝑦(-g‘𝑆)𝑧) = 0 ↔ 𝑦 = 𝑧))
49	36, 45, 48	3imtr3d 296	. . . 4 ⊢ (((𝐹 ∈ (𝑆 GrpHom 𝑇) ∧ ∀𝑥 ∈ 𝑋 ((𝐹‘𝑥) = 𝑈 → 𝑥 = 0 )) ∧ (𝑦 ∈ 𝑋 ∧ 𝑧 ∈ 𝑋)) → ((𝐹‘𝑦) = (𝐹‘𝑧) → 𝑦 = 𝑧))
50	49	ralrimivva 3156	. . 3 ⊢ ((𝐹 ∈ (𝑆 GrpHom 𝑇) ∧ ∀𝑥 ∈ 𝑋 ((𝐹‘𝑥) = 𝑈 → 𝑥 = 0 )) → ∀𝑦 ∈ 𝑋 ∀𝑧 ∈ 𝑋 ((𝐹‘𝑦) = (𝐹‘𝑧) → 𝑦 = 𝑧))
51		dff13 6991	. . 3 ⊢ (𝐹:𝑋–1-1→𝑌 ↔ (𝐹:𝑋⟶𝑌 ∧ ∀𝑦 ∈ 𝑋 ∀𝑧 ∈ 𝑋 ((𝐹‘𝑦) = (𝐹‘𝑧) → 𝑦 = 𝑧)))
52	20, 50, 51	sylanbrc 586	. 2 ⊢ ((𝐹 ∈ (𝑆 GrpHom 𝑇) ∧ ∀𝑥 ∈ 𝑋 ((𝐹‘𝑥) = 𝑈 → 𝑥 = 0 )) → 𝐹:𝑋–1-1→𝑌)
53	17, 52	impbida 800	1 ⊢ (𝐹 ∈ (𝑆 GrpHom 𝑇) → (𝐹:𝑋–1-1→𝑌 ↔ ∀𝑥 ∈ 𝑋 ((𝐹‘𝑥) = 𝑈 → 𝑥 = 0 )))

Syntax hints:   → wi 4   ↔ wb 209   ∧ wa 399   = wceq 1538   ∈ wcel 2111  ∀wral 3106  ⟶wf 6320  –1-1→wf1 6321  ‘cfv 6324  (class class class)co 7135  Basecbs 16475  0_gc0g 16705  Grpcgrp 18095  -_gcsg 18097   GrpHom cghm 18347

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 1911  ax-6 1970  ax-7 2015  ax-8 2113  ax-9 2121  ax-10 2142  ax-11 2158  ax-12 2175  ax-ext 2770  ax-rep 5154  ax-sep 5167  ax-nul 5174  ax-pow 5231  ax-pr 5295  ax-un 7441

This theorem depends on definitions:  df-bi 210  df-an 400  df-or 845  df-3an 1086  df-tru 1541  df-ex 1782  df-nf 1786  df-sb 2070  df-mo 2598  df-eu 2629  df-clab 2777  df-cleq 2791  df-clel 2870  df-nfc 2938  df-ne 2988  df-ral 3111  df-rex 3112  df-reu 3113  df-rmo 3114  df-rab 3115  df-v 3443  df-sbc 3721  df-csb 3829  df-dif 3884  df-un 3886  df-in 3888  df-ss 3898  df-nul 4244  df-if 4426  df-pw 4499  df-sn 4526  df-pr 4528  df-op 4532  df-uni 4801  df-iun 4883  df-br 5031  df-opab 5093  df-mpt 5111  df-id 5425  df-xp 5525  df-rel 5526  df-cnv 5527  df-co 5528  df-dm 5529  df-rn 5530  df-res 5531  df-ima 5532  df-iota 6283  df-fun 6326  df-fn 6327  df-f 6328  df-f1 6329  df-fo 6330  df-f1o 6331  df-fv 6332  df-riota 7093  df-ov 7138  df-oprab 7139  df-mpo 7140  df-1st 7671  df-2nd 7672  df-0g 16707  df-mgm 17844  df-sgrp 17893  df-mnd 17904  df-grp 18098  df-minusg 18099  df-sbg 18100  df-ghm 18348

This theorem is referenced by:  cayleylem2  18533  f1rhm0to0ALT  19489  fidomndrnglem  20072  islindf5  20528  pwssplit4  40033