Theorem ghmgrp1 19115

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 2729	. . . 4 ⊢ (Base‘𝑆) = (Base‘𝑆)
2		eqid 2729	. . . 4 ⊢ (Base‘𝑇) = (Base‘𝑇)
3		eqid 2729	. . . 4 ⊢ (+g‘𝑆) = (+g‘𝑆)
4		eqid 2729	. . . 4 ⊢ (+g‘𝑇) = (+g‘𝑇)
5	1, 2, 3, 4	isghm 19112	. . 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 1540   ∈ wcel 2109  ∀wral 3044  ⟶wf 6482  ‘cfv 6486  (class class class)co 7353  Basecbs 17138  +_gcplusg 17179  Grpcgrp 18830   GrpHom cghm 19109

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 2701  ax-sep 5238  ax-nul 5248  ax-pow 5307  ax-pr 5374  ax-un 7675

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 2533  df-eu 2562  df-clab 2708  df-cleq 2721  df-clel 2803  df-nfc 2878  df-ne 2926  df-ral 3045  df-rex 3054  df-rab 3397  df-v 3440  df-sbc 3745  df-csb 3854  df-dif 3908  df-un 3910  df-in 3912  df-ss 3922  df-nul 4287  df-if 4479  df-pw 4555  df-sn 4580  df-pr 4582  df-op 4586  df-uni 4862  df-iun 4946  df-br 5096  df-opab 5158  df-mpt 5177  df-id 5518  df-xp 5629  df-rel 5630  df-cnv 5631  df-co 5632  df-dm 5633  df-rn 5634  df-res 5635  df-ima 5636  df-iota 6442  df-fun 6488  df-fn 6489  df-f 6490  df-fv 6494  df-ov 7356  df-oprab 7357  df-mpo 7358  df-1st 7931  df-2nd 7932  df-map 8762  df-ghm 19110

This theorem is referenced by:  ghmid  19119  ghminv  19120  ghmsub  19121  ghmmhm  19123  ghmmulg  19125  ghmrn  19126  resghm2  19130  resghm2b  19131  ghmco  19133  ghmpreima  19135  ghmeql  19136  ghmnsgima  19137  ghmnsgpreima  19138  ghmeqker  19140  f1ghm0to0  19142  ghmf1  19143  kerf1ghm  19144  ghmf1o  19145  ghmpropd  19153  isgim  19159  giclcl  19170  ghmqusnsglem1  19177  ghmqusnsglem2  19178  ghmqusnsg  19179  ghmquskerlem1  19180  ghmquskerlem2  19182  ghmquskerlem3  19183  ghmqusker  19184  lactghmga  19302  invghm  19730  ghmplusg  19743  evl1addd  22244  evl1subd  22245  ghmcnp  24018  evlsaddval  42541  evladdval  42548  gicabl  43072