Theorem ghmgrp1 19191

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 2740	. . . 4 ⊢ (Base‘𝑆) = (Base‘𝑆)
2		eqid 2740	. . . 4 ⊢ (Base‘𝑇) = (Base‘𝑇)
3		eqid 2740	. . . 4 ⊢ (+g‘𝑆) = (+g‘𝑆)
4		eqid 2740	. . . 4 ⊢ (+g‘𝑇) = (+g‘𝑇)
5	1, 2, 3, 4	isghm 19188	. . 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 495	1 ⊢ (𝐹 ∈ (𝑆 GrpHom 𝑇) → 𝑆 ∈ Grp)

Syntax hints:   → wi 4   ∧ wa 396   = wceq 1547   ∈ wcel 2119  ∀wral 3054  ⟶wf 6488  ‘cfv 6492  (class class class)co 7363  Basecbs 17177  +_gcplusg 17218  Grpcgrp 18907   GrpHom cghm 19185

This theorem was proved from axioms:  ax-mp 5  ax-1 6  ax-2 7  ax-3 8  ax-gen 1802  ax-4 1816  ax-5 1917  ax-6 1974  ax-7 2015  ax-8 2121  ax-9 2129  ax-10 2152  ax-11 2168  ax-12 2189  ax-ext 2712  ax-sep 5225  ax-nul 5235  ax-pow 5301  ax-pr 5369  ax-un 7685

This theorem depends on definitions:  df-bi 208  df-an 397  df-or 854  df-3an 1094  df-tru 1550  df-fal 1560  df-ex 1787  df-nf 1791  df-sb 2074  df-mo 2543  df-eu 2573  df-clab 2719  df-cleq 2732  df-clel 2815  df-nfc 2889  df-ne 2936  df-ral 3055  df-rex 3065  df-rab 3393  df-v 3434  df-sbc 3731  df-csb 3839  df-dif 3893  df-un 3895  df-in 3897  df-ss 3907  df-nul 4269  df-if 4462  df-pw 4538  df-sn 4563  df-pr 4565  df-op 4569  df-uni 4846  df-iun 4930  df-br 5080  df-opab 5142  df-mpt 5161  df-id 5520  df-xp 5631  df-rel 5632  df-cnv 5633  df-co 5634  df-dm 5635  df-rn 5636  df-res 5637  df-ima 5638  df-iota 6448  df-fun 6494  df-fn 6495  df-f 6496  df-fv 6500  df-ov 7366  df-oprab 7367  df-mpo 7368  df-1st 7938  df-2nd 7939  df-map 8772  df-ghm 19186

This theorem is referenced by:  ghmid  19195  ghminv  19196  ghmsub  19197  ghmmhm  19199  ghmmulg  19201  ghmrn  19202  resghm2  19206  resghm2b  19207  ghmco  19209  ghmpreima  19211  ghmeql  19212  ghmnsgima  19213  ghmnsgpreima  19214  ghmeqker  19216  f1ghm0to0  19218  ghmf1  19219  kerf1ghm  19220  ghmf1o  19221  ghmpropd  19229  isgim  19235  giclcl  19246  ghmqusnsglem1  19253  ghmqusnsglem2  19254  ghmqusnsg  19255  ghmquskerlem1  19256  ghmquskerlem2  19258  ghmquskerlem3  19259  ghmqusker  19260  lactghmga  19378  invghm  19806  ghmplusg  19819  evladdval  22086  evlsaddval  22112  evl1addd  22334  evl1subd  22335  ghmcnp  24105  fxpsubg  33261  gicabl  43551