|   | Metamath Proof Explorer | < Previous  
      Next > Nearby theorems | |
| Mirrors > Home > MPE Home > Th. List > qusghm | Structured version Visualization version GIF version | ||
| Description: If 𝑌 is a normal subgroup of 𝐺, then the "natural map" from elements to their cosets is a group homomorphism from 𝐺 to 𝐺 / 𝑌. (Contributed by Mario Carneiro, 14-Jun-2015.) (Revised by Mario Carneiro, 18-Sep-2015.) | 
| Ref | Expression | 
|---|---|
| qusghm.x | ⊢ 𝑋 = (Base‘𝐺) | 
| qusghm.h | ⊢ 𝐻 = (𝐺 /s (𝐺 ~QG 𝑌)) | 
| qusghm.f | ⊢ 𝐹 = (𝑥 ∈ 𝑋 ↦ [𝑥](𝐺 ~QG 𝑌)) | 
| Ref | Expression | 
|---|---|
| qusghm | ⊢ (𝑌 ∈ (NrmSGrp‘𝐺) → 𝐹 ∈ (𝐺 GrpHom 𝐻)) | 
| Step | Hyp | Ref | Expression | 
|---|---|---|---|
| 1 | qusghm.x | . 2 ⊢ 𝑋 = (Base‘𝐺) | |
| 2 | eqid 2736 | . 2 ⊢ (Base‘𝐻) = (Base‘𝐻) | |
| 3 | eqid 2736 | . 2 ⊢ (+g‘𝐺) = (+g‘𝐺) | |
| 4 | eqid 2736 | . 2 ⊢ (+g‘𝐻) = (+g‘𝐻) | |
| 5 | nsgsubg 19177 | . . 3 ⊢ (𝑌 ∈ (NrmSGrp‘𝐺) → 𝑌 ∈ (SubGrp‘𝐺)) | |
| 6 | subgrcl 19150 | . . 3 ⊢ (𝑌 ∈ (SubGrp‘𝐺) → 𝐺 ∈ Grp) | |
| 7 | 5, 6 | syl 17 | . 2 ⊢ (𝑌 ∈ (NrmSGrp‘𝐺) → 𝐺 ∈ Grp) | 
| 8 | qusghm.h | . . 3 ⊢ 𝐻 = (𝐺 /s (𝐺 ~QG 𝑌)) | |
| 9 | 8 | qusgrp 19205 | . 2 ⊢ (𝑌 ∈ (NrmSGrp‘𝐺) → 𝐻 ∈ Grp) | 
| 10 | 8, 1, 2 | quseccl 19206 | . . 3 ⊢ ((𝑌 ∈ (NrmSGrp‘𝐺) ∧ 𝑥 ∈ 𝑋) → [𝑥](𝐺 ~QG 𝑌) ∈ (Base‘𝐻)) | 
| 11 | qusghm.f | . . 3 ⊢ 𝐹 = (𝑥 ∈ 𝑋 ↦ [𝑥](𝐺 ~QG 𝑌)) | |
| 12 | 10, 11 | fmptd 7133 | . 2 ⊢ (𝑌 ∈ (NrmSGrp‘𝐺) → 𝐹:𝑋⟶(Base‘𝐻)) | 
| 13 | 8, 1, 3, 4 | qusadd 19207 | . . . 4 ⊢ ((𝑌 ∈ (NrmSGrp‘𝐺) ∧ 𝑦 ∈ 𝑋 ∧ 𝑧 ∈ 𝑋) → ([𝑦](𝐺 ~QG 𝑌)(+g‘𝐻)[𝑧](𝐺 ~QG 𝑌)) = [(𝑦(+g‘𝐺)𝑧)](𝐺 ~QG 𝑌)) | 
| 14 | 13 | 3expb 1120 | . . 3 ⊢ ((𝑌 ∈ (NrmSGrp‘𝐺) ∧ (𝑦 ∈ 𝑋 ∧ 𝑧 ∈ 𝑋)) → ([𝑦](𝐺 ~QG 𝑌)(+g‘𝐻)[𝑧](𝐺 ~QG 𝑌)) = [(𝑦(+g‘𝐺)𝑧)](𝐺 ~QG 𝑌)) | 
| 15 | eceq1 8785 | . . . . . 6 ⊢ (𝑥 = 𝑦 → [𝑥](𝐺 ~QG 𝑌) = [𝑦](𝐺 ~QG 𝑌)) | |
| 16 | ovex 7465 | . . . . . . 7 ⊢ (𝐺 ~QG 𝑌) ∈ V | |
| 17 | ecexg 8750 | . . . . . . 7 ⊢ ((𝐺 ~QG 𝑌) ∈ V → [𝑥](𝐺 ~QG 𝑌) ∈ V) | |
| 18 | 16, 17 | ax-mp 5 | . . . . . 6 ⊢ [𝑥](𝐺 ~QG 𝑌) ∈ V | 
| 19 | 15, 11, 18 | fvmpt3i 7020 | . . . . 5 ⊢ (𝑦 ∈ 𝑋 → (𝐹‘𝑦) = [𝑦](𝐺 ~QG 𝑌)) | 
| 20 | 19 | ad2antrl 728 | . . . 4 ⊢ ((𝑌 ∈ (NrmSGrp‘𝐺) ∧ (𝑦 ∈ 𝑋 ∧ 𝑧 ∈ 𝑋)) → (𝐹‘𝑦) = [𝑦](𝐺 ~QG 𝑌)) | 
| 21 | eceq1 8785 | . . . . . 6 ⊢ (𝑥 = 𝑧 → [𝑥](𝐺 ~QG 𝑌) = [𝑧](𝐺 ~QG 𝑌)) | |
| 22 | 21, 11, 18 | fvmpt3i 7020 | . . . . 5 ⊢ (𝑧 ∈ 𝑋 → (𝐹‘𝑧) = [𝑧](𝐺 ~QG 𝑌)) | 
| 23 | 22 | ad2antll 729 | . . . 4 ⊢ ((𝑌 ∈ (NrmSGrp‘𝐺) ∧ (𝑦 ∈ 𝑋 ∧ 𝑧 ∈ 𝑋)) → (𝐹‘𝑧) = [𝑧](𝐺 ~QG 𝑌)) | 
| 24 | 20, 23 | oveq12d 7450 | . . 3 ⊢ ((𝑌 ∈ (NrmSGrp‘𝐺) ∧ (𝑦 ∈ 𝑋 ∧ 𝑧 ∈ 𝑋)) → ((𝐹‘𝑦)(+g‘𝐻)(𝐹‘𝑧)) = ([𝑦](𝐺 ~QG 𝑌)(+g‘𝐻)[𝑧](𝐺 ~QG 𝑌))) | 
| 25 | 1, 3 | grpcl 18960 | . . . . . 6 ⊢ ((𝐺 ∈ Grp ∧ 𝑦 ∈ 𝑋 ∧ 𝑧 ∈ 𝑋) → (𝑦(+g‘𝐺)𝑧) ∈ 𝑋) | 
| 26 | 25 | 3expb 1120 | . . . . 5 ⊢ ((𝐺 ∈ Grp ∧ (𝑦 ∈ 𝑋 ∧ 𝑧 ∈ 𝑋)) → (𝑦(+g‘𝐺)𝑧) ∈ 𝑋) | 
| 27 | 7, 26 | sylan 580 | . . . 4 ⊢ ((𝑌 ∈ (NrmSGrp‘𝐺) ∧ (𝑦 ∈ 𝑋 ∧ 𝑧 ∈ 𝑋)) → (𝑦(+g‘𝐺)𝑧) ∈ 𝑋) | 
| 28 | eceq1 8785 | . . . . 5 ⊢ (𝑥 = (𝑦(+g‘𝐺)𝑧) → [𝑥](𝐺 ~QG 𝑌) = [(𝑦(+g‘𝐺)𝑧)](𝐺 ~QG 𝑌)) | |
| 29 | 28, 11, 18 | fvmpt3i 7020 | . . . 4 ⊢ ((𝑦(+g‘𝐺)𝑧) ∈ 𝑋 → (𝐹‘(𝑦(+g‘𝐺)𝑧)) = [(𝑦(+g‘𝐺)𝑧)](𝐺 ~QG 𝑌)) | 
| 30 | 27, 29 | syl 17 | . . 3 ⊢ ((𝑌 ∈ (NrmSGrp‘𝐺) ∧ (𝑦 ∈ 𝑋 ∧ 𝑧 ∈ 𝑋)) → (𝐹‘(𝑦(+g‘𝐺)𝑧)) = [(𝑦(+g‘𝐺)𝑧)](𝐺 ~QG 𝑌)) | 
| 31 | 14, 24, 30 | 3eqtr4rd 2787 | . 2 ⊢ ((𝑌 ∈ (NrmSGrp‘𝐺) ∧ (𝑦 ∈ 𝑋 ∧ 𝑧 ∈ 𝑋)) → (𝐹‘(𝑦(+g‘𝐺)𝑧)) = ((𝐹‘𝑦)(+g‘𝐻)(𝐹‘𝑧))) | 
| 32 | 1, 2, 3, 4, 7, 9, 12, 31 | isghmd 19244 | 1 ⊢ (𝑌 ∈ (NrmSGrp‘𝐺) → 𝐹 ∈ (𝐺 GrpHom 𝐻)) | 
| Colors of variables: wff setvar class | 
| Syntax hints: → wi 4 ∧ wa 395 = wceq 1539 ∈ wcel 2107 Vcvv 3479 ↦ cmpt 5224 ‘cfv 6560 (class class class)co 7432 [cec 8744 Basecbs 17248 +gcplusg 17298 /s cqus 17551 Grpcgrp 18952 SubGrpcsubg 19139 NrmSGrpcnsg 19140 ~QG cqg 19141 GrpHom cghm 19231 | 
| This theorem was proved from axioms: ax-mp 5 ax-1 6 ax-2 7 ax-3 8 ax-gen 1794 ax-4 1808 ax-5 1909 ax-6 1966 ax-7 2006 ax-8 2109 ax-9 2117 ax-10 2140 ax-11 2156 ax-12 2176 ax-ext 2707 ax-rep 5278 ax-sep 5295 ax-nul 5305 ax-pow 5364 ax-pr 5431 ax-un 7756 ax-cnex 11212 ax-resscn 11213 ax-1cn 11214 ax-icn 11215 ax-addcl 11216 ax-addrcl 11217 ax-mulcl 11218 ax-mulrcl 11219 ax-mulcom 11220 ax-addass 11221 ax-mulass 11222 ax-distr 11223 ax-i2m1 11224 ax-1ne0 11225 ax-1rid 11226 ax-rnegex 11227 ax-rrecex 11228 ax-cnre 11229 ax-pre-lttri 11230 ax-pre-lttrn 11231 ax-pre-ltadd 11232 ax-pre-mulgt0 11233 | 
| This theorem depends on definitions: df-bi 207 df-an 396 df-or 848 df-3or 1087 df-3an 1088 df-tru 1542 df-fal 1552 df-ex 1779 df-nf 1783 df-sb 2064 df-mo 2539 df-eu 2568 df-clab 2714 df-cleq 2728 df-clel 2815 df-nfc 2891 df-ne 2940 df-nel 3046 df-ral 3061 df-rex 3070 df-rmo 3379 df-reu 3380 df-rab 3436 df-v 3481 df-sbc 3788 df-csb 3899 df-dif 3953 df-un 3955 df-in 3957 df-ss 3967 df-pss 3970 df-nul 4333 df-if 4525 df-pw 4601 df-sn 4626 df-pr 4628 df-tp 4630 df-op 4632 df-uni 4907 df-iun 4992 df-br 5143 df-opab 5205 df-mpt 5225 df-tr 5259 df-id 5577 df-eprel 5583 df-po 5591 df-so 5592 df-fr 5636 df-we 5638 df-xp 5690 df-rel 5691 df-cnv 5692 df-co 5693 df-dm 5694 df-rn 5695 df-res 5696 df-ima 5697 df-pred 6320 df-ord 6386 df-on 6387 df-lim 6388 df-suc 6389 df-iota 6513 df-fun 6562 df-fn 6563 df-f 6564 df-f1 6565 df-fo 6566 df-f1o 6567 df-fv 6568 df-riota 7389 df-ov 7435 df-oprab 7436 df-mpo 7437 df-om 7889 df-1st 8015 df-2nd 8016 df-frecs 8307 df-wrecs 8338 df-recs 8412 df-rdg 8451 df-1o 8507 df-er 8746 df-ec 8748 df-qs 8752 df-map 8869 df-en 8987 df-dom 8988 df-sdom 8989 df-fin 8990 df-sup 9483 df-inf 9484 df-pnf 11298 df-mnf 11299 df-xr 11300 df-ltxr 11301 df-le 11302 df-sub 11495 df-neg 11496 df-nn 12268 df-2 12330 df-3 12331 df-4 12332 df-5 12333 df-6 12334 df-7 12335 df-8 12336 df-9 12337 df-n0 12529 df-z 12616 df-dec 12736 df-uz 12880 df-fz 13549 df-struct 17185 df-sets 17202 df-slot 17220 df-ndx 17232 df-base 17249 df-ress 17276 df-plusg 17311 df-mulr 17312 df-sca 17314 df-vsca 17315 df-ip 17316 df-tset 17317 df-ple 17318 df-ds 17320 df-0g 17487 df-imas 17554 df-qus 17555 df-mgm 18654 df-sgrp 18733 df-mnd 18749 df-grp 18955 df-minusg 18956 df-subg 19142 df-nsg 19143 df-eqg 19144 df-ghm 19232 | 
| This theorem is referenced by: qusrhm 21287 quslmhm 33388 nsgmgc 33441 | 
| Copyright terms: Public domain | W3C validator |