Theorem ghmgrp1 19134

Description: A group homomorphism is only defined when the domain is a group. (Contributed by Stefan O'Rear, 31-Dec-2014.)

Assertion

Ref	Expression
ghmgrp1	⊢ (𝐹 ∈ (𝑆 GrpHom 𝑇) → 𝑆 ∈ Grp)

Proof of Theorem ghmgrp1

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

Step	Hyp	Ref	Expression
1		eqid 2733	. . . 4 ⊢ (Base‘𝑆) = (Base‘𝑆)
2		eqid 2733	. . . 4 ⊢ (Base‘𝑇) = (Base‘𝑇)
3		eqid 2733	. . . 4 ⊢ (+g‘𝑆) = (+g‘𝑆)
4		eqid 2733	. . . 4 ⊢ (+g‘𝑇) = (+g‘𝑇)
5	1, 2, 3, 4	isghm 19131	. . 3 ⊢ (𝐹 ∈ (𝑆 GrpHom 𝑇) ↔ ((𝑆 ∈ Grp ∧ 𝑇 ∈ Grp) ∧ (𝐹:(Base‘𝑆)⟶(Base‘𝑇) ∧ ∀𝑦 ∈ (Base‘𝑆)∀𝑥 ∈ (Base‘𝑆)(𝐹‘(𝑦(+g‘𝑆)𝑥)) = ((𝐹‘𝑦)(+g‘𝑇)(𝐹‘𝑥)))))
6	5	simplbi 497	. 2 ⊢ (𝐹 ∈ (𝑆 GrpHom 𝑇) → (𝑆 ∈ Grp ∧ 𝑇 ∈ Grp))
7	6	simpld 494	1 ⊢ (𝐹 ∈ (𝑆 GrpHom 𝑇) → 𝑆 ∈ Grp)

Syntax hints:   → wi 4   ∧ wa 395   = wceq 1541   ∈ wcel 2113  ∀wral 3048  ⟶wf 6484  ‘cfv 6488  (class class class)co 7354  Basecbs 17124  +_gcplusg 17165  Grpcgrp 18850   GrpHom cghm 19128

This theorem was proved from axioms:  ax-mp 5  ax-1 6  ax-2 7  ax-3 8  ax-gen 1796  ax-4 1810  ax-5 1911  ax-6 1968  ax-7 2009  ax-8 2115  ax-9 2123  ax-10 2146  ax-11 2162  ax-12 2182  ax-ext 2705  ax-sep 5238  ax-nul 5248  ax-pow 5307  ax-pr 5374  ax-un 7676

This theorem depends on definitions:  df-bi 207  df-an 396  df-or 848  df-3an 1088  df-tru 1544  df-fal 1554  df-ex 1781  df-nf 1785  df-sb 2068  df-mo 2537  df-eu 2566  df-clab 2712  df-cleq 2725  df-clel 2808  df-nfc 2882  df-ne 2930  df-ral 3049  df-rex 3058  df-rab 3397  df-v 3439  df-sbc 3738  df-csb 3847  df-dif 3901  df-un 3903  df-in 3905  df-ss 3915  df-nul 4283  df-if 4477  df-pw 4553  df-sn 4578  df-pr 4580  df-op 4584  df-uni 4861  df-iun 4945  df-br 5096  df-opab 5158  df-mpt 5177  df-id 5516  df-xp 5627  df-rel 5628  df-cnv 5629  df-co 5630  df-dm 5631  df-rn 5632  df-res 5633  df-ima 5634  df-iota 6444  df-fun 6490  df-fn 6491  df-f 6492  df-fv 6496  df-ov 7357  df-oprab 7358  df-mpo 7359  df-1st 7929  df-2nd 7930  df-map 8760  df-ghm 19129

This theorem is referenced by:  ghmid  19138  ghminv  19139  ghmsub  19140  ghmmhm  19142  ghmmulg  19144  ghmrn  19145  resghm2  19149  resghm2b  19150  ghmco  19152  ghmpreima  19154  ghmeql  19155  ghmnsgima  19156  ghmnsgpreima  19157  ghmeqker  19159  f1ghm0to0  19161  ghmf1  19162  kerf1ghm  19163  ghmf1o  19164  ghmpropd  19172  isgim  19178  giclcl  19189  ghmqusnsglem1  19196  ghmqusnsglem2  19197  ghmqusnsg  19198  ghmquskerlem1  19199  ghmquskerlem2  19201  ghmquskerlem3  19202  ghmqusker  19203  lactghmga  19321  invghm  19749  ghmplusg  19762  evl1addd  22259  evl1subd  22260  ghmcnp  24033  fxpsubg  33151  evlsaddval  42689  evladdval  42696  gicabl  43219