Theorem ghmf1 19185

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.) (Proof shortened by AV, 4-Apr-2025.)

Hypotheses

Ref	Expression
f1ghm0to0.a	⊢ 𝐴 = (Base‘𝑅)
f1ghm0to0.b	⊢ 𝐵 = (Base‘𝑆)
f1ghm0to0.n	⊢ 𝑁 = (0g‘𝑅)
f1ghm0to0.0	⊢ 0 = (0g‘𝑆)

Assertion

Ref	Expression
ghmf1	⊢ (𝐹 ∈ (𝑅 GrpHom 𝑆) → (𝐹:𝐴–1-1→𝐵 ↔ ∀𝑥 ∈ 𝐴 ((𝐹‘𝑥) = 0 → 𝑥 = 𝑁)))

Distinct variable groups:   𝑥, 0   𝑥,𝐴   𝑥,𝐵   𝑥,𝐹   𝑥,𝑁   𝑥,𝑅   𝑥,𝑆

Proof of Theorem ghmf1

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

Step	Hyp	Ref	Expression
1		f1ghm0to0.a	. . . . . 6 ⊢ 𝐴 = (Base‘𝑅)
2		f1ghm0to0.b	. . . . . 6 ⊢ 𝐵 = (Base‘𝑆)
3		f1ghm0to0.n	. . . . . 6 ⊢ 𝑁 = (0g‘𝑅)
4		f1ghm0to0.0	. . . . . 6 ⊢ 0 = (0g‘𝑆)
5	1, 2, 3, 4	f1ghm0to0 19184	. . . . 5 ⊢ ((𝐹 ∈ (𝑅 GrpHom 𝑆) ∧ 𝐹:𝐴–1-1→𝐵 ∧ 𝑥 ∈ 𝐴) → ((𝐹‘𝑥) = 0 ↔ 𝑥 = 𝑁))
6	5	3expa 1118	. . . 4 ⊢ (((𝐹 ∈ (𝑅 GrpHom 𝑆) ∧ 𝐹:𝐴–1-1→𝐵) ∧ 𝑥 ∈ 𝐴) → ((𝐹‘𝑥) = 0 ↔ 𝑥 = 𝑁))
7	6	biimpd 229	. . 3 ⊢ (((𝐹 ∈ (𝑅 GrpHom 𝑆) ∧ 𝐹:𝐴–1-1→𝐵) ∧ 𝑥 ∈ 𝐴) → ((𝐹‘𝑥) = 0 → 𝑥 = 𝑁))
8	7	ralrimiva 3126	. 2 ⊢ ((𝐹 ∈ (𝑅 GrpHom 𝑆) ∧ 𝐹:𝐴–1-1→𝐵) → ∀𝑥 ∈ 𝐴 ((𝐹‘𝑥) = 0 → 𝑥 = 𝑁))
9	1, 2	ghmf 19159	. . . 4 ⊢ (𝐹 ∈ (𝑅 GrpHom 𝑆) → 𝐹:𝐴⟶𝐵)
10	9	adantr 480	. . 3 ⊢ ((𝐹 ∈ (𝑅 GrpHom 𝑆) ∧ ∀𝑥 ∈ 𝐴 ((𝐹‘𝑥) = 0 → 𝑥 = 𝑁)) → 𝐹:𝐴⟶𝐵)
11		eqid 2730	. . . . . . . . . 10 ⊢ (-g‘𝑅) = (-g‘𝑅)
12		eqid 2730	. . . . . . . . . 10 ⊢ (-g‘𝑆) = (-g‘𝑆)
13	1, 11, 12	ghmsub 19163	. . . . . . . . 9 ⊢ ((𝐹 ∈ (𝑅 GrpHom 𝑆) ∧ 𝑦 ∈ 𝐴 ∧ 𝑧 ∈ 𝐴) → (𝐹‘(𝑦(-g‘𝑅)𝑧)) = ((𝐹‘𝑦)(-g‘𝑆)(𝐹‘𝑧)))
14	13	3expb 1120	. . . . . . . 8 ⊢ ((𝐹 ∈ (𝑅 GrpHom 𝑆) ∧ (𝑦 ∈ 𝐴 ∧ 𝑧 ∈ 𝐴)) → (𝐹‘(𝑦(-g‘𝑅)𝑧)) = ((𝐹‘𝑦)(-g‘𝑆)(𝐹‘𝑧)))
15	14	adantlr 715	. . . . . . 7 ⊢ (((𝐹 ∈ (𝑅 GrpHom 𝑆) ∧ ∀𝑥 ∈ 𝐴 ((𝐹‘𝑥) = 0 → 𝑥 = 𝑁)) ∧ (𝑦 ∈ 𝐴 ∧ 𝑧 ∈ 𝐴)) → (𝐹‘(𝑦(-g‘𝑅)𝑧)) = ((𝐹‘𝑦)(-g‘𝑆)(𝐹‘𝑧)))
16	15	eqeq1d 2732	. . . . . 6 ⊢ (((𝐹 ∈ (𝑅 GrpHom 𝑆) ∧ ∀𝑥 ∈ 𝐴 ((𝐹‘𝑥) = 0 → 𝑥 = 𝑁)) ∧ (𝑦 ∈ 𝐴 ∧ 𝑧 ∈ 𝐴)) → ((𝐹‘(𝑦(-g‘𝑅)𝑧)) = 0 ↔ ((𝐹‘𝑦)(-g‘𝑆)(𝐹‘𝑧)) = 0 ))
17		fveqeq2 6870	. . . . . . . 8 ⊢ (𝑥 = (𝑦(-g‘𝑅)𝑧) → ((𝐹‘𝑥) = 0 ↔ (𝐹‘(𝑦(-g‘𝑅)𝑧)) = 0 ))
18		eqeq1 2734	. . . . . . . 8 ⊢ (𝑥 = (𝑦(-g‘𝑅)𝑧) → (𝑥 = 𝑁 ↔ (𝑦(-g‘𝑅)𝑧) = 𝑁))
19	17, 18	imbi12d 344	. . . . . . 7 ⊢ (𝑥 = (𝑦(-g‘𝑅)𝑧) → (((𝐹‘𝑥) = 0 → 𝑥 = 𝑁) ↔ ((𝐹‘(𝑦(-g‘𝑅)𝑧)) = 0 → (𝑦(-g‘𝑅)𝑧) = 𝑁)))
20		simplr 768	. . . . . . 7 ⊢ (((𝐹 ∈ (𝑅 GrpHom 𝑆) ∧ ∀𝑥 ∈ 𝐴 ((𝐹‘𝑥) = 0 → 𝑥 = 𝑁)) ∧ (𝑦 ∈ 𝐴 ∧ 𝑧 ∈ 𝐴)) → ∀𝑥 ∈ 𝐴 ((𝐹‘𝑥) = 0 → 𝑥 = 𝑁))
21		ghmgrp1 19157	. . . . . . . . 9 ⊢ (𝐹 ∈ (𝑅 GrpHom 𝑆) → 𝑅 ∈ Grp)
22	21	adantr 480	. . . . . . . 8 ⊢ ((𝐹 ∈ (𝑅 GrpHom 𝑆) ∧ ∀𝑥 ∈ 𝐴 ((𝐹‘𝑥) = 0 → 𝑥 = 𝑁)) → 𝑅 ∈ Grp)
23	1, 11	grpsubcl 18959	. . . . . . . . 9 ⊢ ((𝑅 ∈ Grp ∧ 𝑦 ∈ 𝐴 ∧ 𝑧 ∈ 𝐴) → (𝑦(-g‘𝑅)𝑧) ∈ 𝐴)
24	23	3expb 1120	. . . . . . . 8 ⊢ ((𝑅 ∈ Grp ∧ (𝑦 ∈ 𝐴 ∧ 𝑧 ∈ 𝐴)) → (𝑦(-g‘𝑅)𝑧) ∈ 𝐴)
25	22, 24	sylan 580	. . . . . . 7 ⊢ (((𝐹 ∈ (𝑅 GrpHom 𝑆) ∧ ∀𝑥 ∈ 𝐴 ((𝐹‘𝑥) = 0 → 𝑥 = 𝑁)) ∧ (𝑦 ∈ 𝐴 ∧ 𝑧 ∈ 𝐴)) → (𝑦(-g‘𝑅)𝑧) ∈ 𝐴)
26	19, 20, 25	rspcdva 3592	. . . . . 6 ⊢ (((𝐹 ∈ (𝑅 GrpHom 𝑆) ∧ ∀𝑥 ∈ 𝐴 ((𝐹‘𝑥) = 0 → 𝑥 = 𝑁)) ∧ (𝑦 ∈ 𝐴 ∧ 𝑧 ∈ 𝐴)) → ((𝐹‘(𝑦(-g‘𝑅)𝑧)) = 0 → (𝑦(-g‘𝑅)𝑧) = 𝑁))
27	16, 26	sylbird 260	. . . . 5 ⊢ (((𝐹 ∈ (𝑅 GrpHom 𝑆) ∧ ∀𝑥 ∈ 𝐴 ((𝐹‘𝑥) = 0 → 𝑥 = 𝑁)) ∧ (𝑦 ∈ 𝐴 ∧ 𝑧 ∈ 𝐴)) → (((𝐹‘𝑦)(-g‘𝑆)(𝐹‘𝑧)) = 0 → (𝑦(-g‘𝑅)𝑧) = 𝑁))
28		ghmgrp2 19158	. . . . . . 7 ⊢ (𝐹 ∈ (𝑅 GrpHom 𝑆) → 𝑆 ∈ Grp)
29	28	ad2antrr 726	. . . . . 6 ⊢ (((𝐹 ∈ (𝑅 GrpHom 𝑆) ∧ ∀𝑥 ∈ 𝐴 ((𝐹‘𝑥) = 0 → 𝑥 = 𝑁)) ∧ (𝑦 ∈ 𝐴 ∧ 𝑧 ∈ 𝐴)) → 𝑆 ∈ Grp)
30	9	ad2antrr 726	. . . . . . 7 ⊢ (((𝐹 ∈ (𝑅 GrpHom 𝑆) ∧ ∀𝑥 ∈ 𝐴 ((𝐹‘𝑥) = 0 → 𝑥 = 𝑁)) ∧ (𝑦 ∈ 𝐴 ∧ 𝑧 ∈ 𝐴)) → 𝐹:𝐴⟶𝐵)
31		simprl 770	. . . . . . 7 ⊢ (((𝐹 ∈ (𝑅 GrpHom 𝑆) ∧ ∀𝑥 ∈ 𝐴 ((𝐹‘𝑥) = 0 → 𝑥 = 𝑁)) ∧ (𝑦 ∈ 𝐴 ∧ 𝑧 ∈ 𝐴)) → 𝑦 ∈ 𝐴)
32	30, 31	ffvelcdmd 7060	. . . . . 6 ⊢ (((𝐹 ∈ (𝑅 GrpHom 𝑆) ∧ ∀𝑥 ∈ 𝐴 ((𝐹‘𝑥) = 0 → 𝑥 = 𝑁)) ∧ (𝑦 ∈ 𝐴 ∧ 𝑧 ∈ 𝐴)) → (𝐹‘𝑦) ∈ 𝐵)
33		simprr 772	. . . . . . 7 ⊢ (((𝐹 ∈ (𝑅 GrpHom 𝑆) ∧ ∀𝑥 ∈ 𝐴 ((𝐹‘𝑥) = 0 → 𝑥 = 𝑁)) ∧ (𝑦 ∈ 𝐴 ∧ 𝑧 ∈ 𝐴)) → 𝑧 ∈ 𝐴)
34	30, 33	ffvelcdmd 7060	. . . . . 6 ⊢ (((𝐹 ∈ (𝑅 GrpHom 𝑆) ∧ ∀𝑥 ∈ 𝐴 ((𝐹‘𝑥) = 0 → 𝑥 = 𝑁)) ∧ (𝑦 ∈ 𝐴 ∧ 𝑧 ∈ 𝐴)) → (𝐹‘𝑧) ∈ 𝐵)
35	2, 4, 12	grpsubeq0 18965	. . . . . 6 ⊢ ((𝑆 ∈ Grp ∧ (𝐹‘𝑦) ∈ 𝐵 ∧ (𝐹‘𝑧) ∈ 𝐵) → (((𝐹‘𝑦)(-g‘𝑆)(𝐹‘𝑧)) = 0 ↔ (𝐹‘𝑦) = (𝐹‘𝑧)))
36	29, 32, 34, 35	syl3anc 1373	. . . . 5 ⊢ (((𝐹 ∈ (𝑅 GrpHom 𝑆) ∧ ∀𝑥 ∈ 𝐴 ((𝐹‘𝑥) = 0 → 𝑥 = 𝑁)) ∧ (𝑦 ∈ 𝐴 ∧ 𝑧 ∈ 𝐴)) → (((𝐹‘𝑦)(-g‘𝑆)(𝐹‘𝑧)) = 0 ↔ (𝐹‘𝑦) = (𝐹‘𝑧)))
37	21	ad2antrr 726	. . . . . 6 ⊢ (((𝐹 ∈ (𝑅 GrpHom 𝑆) ∧ ∀𝑥 ∈ 𝐴 ((𝐹‘𝑥) = 0 → 𝑥 = 𝑁)) ∧ (𝑦 ∈ 𝐴 ∧ 𝑧 ∈ 𝐴)) → 𝑅 ∈ Grp)
38	1, 3, 11	grpsubeq0 18965	. . . . . 6 ⊢ ((𝑅 ∈ Grp ∧ 𝑦 ∈ 𝐴 ∧ 𝑧 ∈ 𝐴) → ((𝑦(-g‘𝑅)𝑧) = 𝑁 ↔ 𝑦 = 𝑧))
39	37, 31, 33, 38	syl3anc 1373	. . . . 5 ⊢ (((𝐹 ∈ (𝑅 GrpHom 𝑆) ∧ ∀𝑥 ∈ 𝐴 ((𝐹‘𝑥) = 0 → 𝑥 = 𝑁)) ∧ (𝑦 ∈ 𝐴 ∧ 𝑧 ∈ 𝐴)) → ((𝑦(-g‘𝑅)𝑧) = 𝑁 ↔ 𝑦 = 𝑧))
40	27, 36, 39	3imtr3d 293	. . . 4 ⊢ (((𝐹 ∈ (𝑅 GrpHom 𝑆) ∧ ∀𝑥 ∈ 𝐴 ((𝐹‘𝑥) = 0 → 𝑥 = 𝑁)) ∧ (𝑦 ∈ 𝐴 ∧ 𝑧 ∈ 𝐴)) → ((𝐹‘𝑦) = (𝐹‘𝑧) → 𝑦 = 𝑧))
41	40	ralrimivva 3181	. . 3 ⊢ ((𝐹 ∈ (𝑅 GrpHom 𝑆) ∧ ∀𝑥 ∈ 𝐴 ((𝐹‘𝑥) = 0 → 𝑥 = 𝑁)) → ∀𝑦 ∈ 𝐴 ∀𝑧 ∈ 𝐴 ((𝐹‘𝑦) = (𝐹‘𝑧) → 𝑦 = 𝑧))
42		dff13 7232	. . 3 ⊢ (𝐹:𝐴–1-1→𝐵 ↔ (𝐹:𝐴⟶𝐵 ∧ ∀𝑦 ∈ 𝐴 ∀𝑧 ∈ 𝐴 ((𝐹‘𝑦) = (𝐹‘𝑧) → 𝑦 = 𝑧)))
43	10, 41, 42	sylanbrc 583	. 2 ⊢ ((𝐹 ∈ (𝑅 GrpHom 𝑆) ∧ ∀𝑥 ∈ 𝐴 ((𝐹‘𝑥) = 0 → 𝑥 = 𝑁)) → 𝐹:𝐴–1-1→𝐵)
44	8, 43	impbida 800	1 ⊢ (𝐹 ∈ (𝑅 GrpHom 𝑆) → (𝐹:𝐴–1-1→𝐵 ↔ ∀𝑥 ∈ 𝐴 ((𝐹‘𝑥) = 0 → 𝑥 = 𝑁)))

Syntax hints:   → wi 4   ↔ wb 206   ∧ wa 395   = wceq 1540   ∈ wcel 2109  ∀wral 3045  ⟶wf 6510  –1-1→wf1 6511  ‘cfv 6514  (class class class)co 7390  Basecbs 17186  0_gc0g 17409  Grpcgrp 18872  -_gcsg 18874   GrpHom cghm 19151

This theorem was proved from axioms:  ax-mp 5  ax-1 6  ax-2 7  ax-3 8  ax-gen 1795  ax-4 1809  ax-5 1910  ax-6 1967  ax-7 2008  ax-8 2111  ax-9 2119  ax-10 2142  ax-11 2158  ax-12 2178  ax-ext 2702  ax-sep 5254  ax-nul 5264  ax-pow 5323  ax-pr 5390  ax-un 7714

This theorem depends on definitions:  df-bi 207  df-an 396  df-or 848  df-3an 1088  df-tru 1543  df-fal 1553  df-ex 1780  df-nf 1784  df-sb 2066  df-mo 2534  df-eu 2563  df-clab 2709  df-cleq 2722  df-clel 2804  df-nfc 2879  df-ne 2927  df-ral 3046  df-rex 3055  df-rmo 3356  df-reu 3357  df-rab 3409  df-v 3452  df-sbc 3757  df-csb 3866  df-dif 3920  df-un 3922  df-in 3924  df-ss 3934  df-nul 4300  df-if 4492  df-pw 4568  df-sn 4593  df-pr 4595  df-op 4599  df-uni 4875  df-iun 4960  df-br 5111  df-opab 5173  df-mpt 5192  df-id 5536  df-xp 5647  df-rel 5648  df-cnv 5649  df-co 5650  df-dm 5651  df-rn 5652  df-res 5653  df-ima 5654  df-iota 6467  df-fun 6516  df-fn 6517  df-f 6518  df-f1 6519  df-fv 6522  df-riota 7347  df-ov 7393  df-oprab 7394  df-mpo 7395  df-1st 7971  df-2nd 7972  df-map 8804  df-0g 17411  df-mgm 18574  df-sgrp 18653  df-mnd 18669  df-grp 18875  df-minusg 18876  df-sbg 18877  df-ghm 19152

This theorem is referenced by:  cayleylem2  19350  fidomndrnglem  20688  islindf5  21755  asclf1  42526  pwssplit4  43085