Theorem grpinvfval 18908

Description: The inverse function of a group. For a shorter proof using ax-rep 5224, see grpinvfvalALT 18909. (Contributed by NM, 24-Aug-2011.) (Revised by Mario Carneiro, 7-Aug-2013.) Remove dependency on ax-rep 5224. (Revised by Rohan Ridenour, 13-Aug-2023.)

Hypotheses

Ref	Expression
grpinvval.b	⊢ 𝐵 = (Base‘𝐺)
grpinvval.p	⊢ + = (+g‘𝐺)
grpinvval.o	⊢ 0 = (0g‘𝐺)
grpinvval.n	⊢ 𝑁 = (invg‘𝐺)

Assertion

Ref	Expression
grpinvfval	⊢ 𝑁 = (𝑥 ∈ 𝐵 ↦ (℩𝑦 ∈ 𝐵 (𝑦 + 𝑥) = 0 ))

Distinct variable groups:   𝑥,𝑦,𝐵   𝑥,𝐺,𝑦   𝑥, 0   𝑥, +

Allowed substitution hints:   + (𝑦)   𝑁(𝑥,𝑦)   0 (𝑦)

Proof of Theorem grpinvfval

Dummy variable 𝑔 is distinct from all other variables.

Step	Hyp	Ref	Expression
1		grpinvval.n	. 2 ⊢ 𝑁 = (invg‘𝐺)
2		fveq2 6834	. . . . . 6 ⊢ (𝑔 = 𝐺 → (Base‘𝑔) = (Base‘𝐺))
3		grpinvval.b	. . . . . 6 ⊢ 𝐵 = (Base‘𝐺)
4	2, 3	eqtr4di 2789	. . . . 5 ⊢ (𝑔 = 𝐺 → (Base‘𝑔) = 𝐵)
5		fveq2 6834	. . . . . . . . 9 ⊢ (𝑔 = 𝐺 → (+g‘𝑔) = (+g‘𝐺))
6		grpinvval.p	. . . . . . . . 9 ⊢ + = (+g‘𝐺)
7	5, 6	eqtr4di 2789	. . . . . . . 8 ⊢ (𝑔 = 𝐺 → (+g‘𝑔) = + )
8	7	oveqd 7375	. . . . . . 7 ⊢ (𝑔 = 𝐺 → (𝑦(+g‘𝑔)𝑥) = (𝑦 + 𝑥))
9		fveq2 6834	. . . . . . . 8 ⊢ (𝑔 = 𝐺 → (0g‘𝑔) = (0g‘𝐺))
10		grpinvval.o	. . . . . . . 8 ⊢ 0 = (0g‘𝐺)
11	9, 10	eqtr4di 2789	. . . . . . 7 ⊢ (𝑔 = 𝐺 → (0g‘𝑔) = 0 )
12	8, 11	eqeq12d 2752	. . . . . 6 ⊢ (𝑔 = 𝐺 → ((𝑦(+g‘𝑔)𝑥) = (0g‘𝑔) ↔ (𝑦 + 𝑥) = 0 ))
13	4, 12	riotaeqbidv 7318	. . . . 5 ⊢ (𝑔 = 𝐺 → (℩𝑦 ∈ (Base‘𝑔)(𝑦(+g‘𝑔)𝑥) = (0g‘𝑔)) = (℩𝑦 ∈ 𝐵 (𝑦 + 𝑥) = 0 ))
14	4, 13	mpteq12dv 5185	. . . 4 ⊢ (𝑔 = 𝐺 → (𝑥 ∈ (Base‘𝑔) ↦ (℩𝑦 ∈ (Base‘𝑔)(𝑦(+g‘𝑔)𝑥) = (0g‘𝑔))) = (𝑥 ∈ 𝐵 ↦ (℩𝑦 ∈ 𝐵 (𝑦 + 𝑥) = 0 )))
15		df-minusg 18867	. . . 4 ⊢ invg = (𝑔 ∈ V ↦ (𝑥 ∈ (Base‘𝑔) ↦ (℩𝑦 ∈ (Base‘𝑔)(𝑦(+g‘𝑔)𝑥) = (0g‘𝑔))))
16	3	fvexi 6848	. . . . 5 ⊢ 𝐵 ∈ V
17		p0ex 5329	. . . . . 6 ⊢ {∅} ∈ V
18	17, 16	unex 7689	. . . . 5 ⊢ ({∅} ∪ 𝐵) ∈ V
19		ssun2 4131	. . . . . . . 8 ⊢ 𝐵 ⊆ ({∅} ∪ 𝐵)
20		riotacl 7332	. . . . . . . 8 ⊢ (∃!𝑦 ∈ 𝐵 (𝑦 + 𝑥) = 0 → (℩𝑦 ∈ 𝐵 (𝑦 + 𝑥) = 0 ) ∈ 𝐵)
21	19, 20	sselid 3931	. . . . . . 7 ⊢ (∃!𝑦 ∈ 𝐵 (𝑦 + 𝑥) = 0 → (℩𝑦 ∈ 𝐵 (𝑦 + 𝑥) = 0 ) ∈ ({∅} ∪ 𝐵))
22		ssun1 4130	. . . . . . . 8 ⊢ {∅} ⊆ ({∅} ∪ 𝐵)
23		riotaund 7354	. . . . . . . . 9 ⊢ (¬ ∃!𝑦 ∈ 𝐵 (𝑦 + 𝑥) = 0 → (℩𝑦 ∈ 𝐵 (𝑦 + 𝑥) = 0 ) = ∅)
24		riotaex 7319	. . . . . . . . . 10 ⊢ (℩𝑦 ∈ 𝐵 (𝑦 + 𝑥) = 0 ) ∈ V
25	24	elsn 4595	. . . . . . . . 9 ⊢ ((℩𝑦 ∈ 𝐵 (𝑦 + 𝑥) = 0 ) ∈ {∅} ↔ (℩𝑦 ∈ 𝐵 (𝑦 + 𝑥) = 0 ) = ∅)
26	23, 25	sylibr 234	. . . . . . . 8 ⊢ (¬ ∃!𝑦 ∈ 𝐵 (𝑦 + 𝑥) = 0 → (℩𝑦 ∈ 𝐵 (𝑦 + 𝑥) = 0 ) ∈ {∅})
27	22, 26	sselid 3931	. . . . . . 7 ⊢ (¬ ∃!𝑦 ∈ 𝐵 (𝑦 + 𝑥) = 0 → (℩𝑦 ∈ 𝐵 (𝑦 + 𝑥) = 0 ) ∈ ({∅} ∪ 𝐵))
28	21, 27	pm2.61i 182	. . . . . 6 ⊢ (℩𝑦 ∈ 𝐵 (𝑦 + 𝑥) = 0 ) ∈ ({∅} ∪ 𝐵)
29	28	rgenw 3055	. . . . 5 ⊢ ∀𝑥 ∈ 𝐵 (℩𝑦 ∈ 𝐵 (𝑦 + 𝑥) = 0 ) ∈ ({∅} ∪ 𝐵)
30	16, 18, 29	mptexw 7897	. . . 4 ⊢ (𝑥 ∈ 𝐵 ↦ (℩𝑦 ∈ 𝐵 (𝑦 + 𝑥) = 0 )) ∈ V
31	14, 15, 30	fvmpt 6941	. . 3 ⊢ (𝐺 ∈ V → (invg‘𝐺) = (𝑥 ∈ 𝐵 ↦ (℩𝑦 ∈ 𝐵 (𝑦 + 𝑥) = 0 )))
32		fvprc 6826	. . . . 5 ⊢ (¬ 𝐺 ∈ V → (invg‘𝐺) = ∅)
33		mpt0 6634	. . . . 5 ⊢ (𝑥 ∈ ∅ ↦ (℩𝑦 ∈ 𝐵 (𝑦 + 𝑥) = 0 )) = ∅
34	32, 33	eqtr4di 2789	. . . 4 ⊢ (¬ 𝐺 ∈ V → (invg‘𝐺) = (𝑥 ∈ ∅ ↦ (℩𝑦 ∈ 𝐵 (𝑦 + 𝑥) = 0 )))
35		fvprc 6826	. . . . . 6 ⊢ (¬ 𝐺 ∈ V → (Base‘𝐺) = ∅)
36	3, 35	eqtrid 2783	. . . . 5 ⊢ (¬ 𝐺 ∈ V → 𝐵 = ∅)
37	36	mpteq1d 5188	. . . 4 ⊢ (¬ 𝐺 ∈ V → (𝑥 ∈ 𝐵 ↦ (℩𝑦 ∈ 𝐵 (𝑦 + 𝑥) = 0 )) = (𝑥 ∈ ∅ ↦ (℩𝑦 ∈ 𝐵 (𝑦 + 𝑥) = 0 )))
38	34, 37	eqtr4d 2774	. . 3 ⊢ (¬ 𝐺 ∈ V → (invg‘𝐺) = (𝑥 ∈ 𝐵 ↦ (℩𝑦 ∈ 𝐵 (𝑦 + 𝑥) = 0 )))
39	31, 38	pm2.61i 182	. 2 ⊢ (invg‘𝐺) = (𝑥 ∈ 𝐵 ↦ (℩𝑦 ∈ 𝐵 (𝑦 + 𝑥) = 0 ))
40	1, 39	eqtri 2759	1 ⊢ 𝑁 = (𝑥 ∈ 𝐵 ↦ (℩𝑦 ∈ 𝐵 (𝑦 + 𝑥) = 0 ))

Syntax hints:  ¬ wn 3   = wceq 1541   ∈ wcel 2113  ∃!wreu 3348  Vcvv 3440   ∪ cun 3899  ∅c0 4285  {csn 4580   ↦ cmpt 5179  ‘cfv 6492  ℩crio 7314  (class class class)co 7358  Basecbs 17136  +_gcplusg 17177  0_gc0g 17359  inv_gcminusg 18864

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 2184  ax-ext 2708  ax-sep 5241  ax-nul 5251  ax-pow 5310  ax-pr 5377  ax-un 7680

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 2539  df-eu 2569  df-clab 2715  df-cleq 2728  df-clel 2811  df-nfc 2885  df-ne 2933  df-ral 3052  df-rex 3061  df-reu 3351  df-rab 3400  df-v 3442  df-sbc 3741  df-dif 3904  df-un 3906  df-in 3908  df-ss 3918  df-nul 4286  df-if 4480  df-pw 4556  df-sn 4581  df-pr 4583  df-op 4587  df-uni 4864  df-br 5099  df-opab 5161  df-mpt 5180  df-id 5519  df-xp 5630  df-rel 5631  df-cnv 5632  df-co 5633  df-dm 5634  df-rn 5635  df-res 5636  df-ima 5637  df-iota 6448  df-fun 6494  df-fn 6495  df-f 6496  df-fv 6500  df-riota 7315  df-ov 7361  df-minusg 18867

This theorem is referenced by:  grpinvval  18910  grpinvfn  18911  grpinvf  18916  grpinvpropd  18945  opprneg  20287