Theorem qusgrp2 17533

Description: Prove that a quotient structure is a group. (Contributed by Mario Carneiro, 14-Jun-2015.) (Revised by Mario Carneiro, 12-Aug-2015.)

Hypotheses

Ref	Expression
qusgrp2.u	|- ( ph -> U = ( R /.s .~ ) )
qusgrp2.v	|- ( ph -> V = ( Base ` R ) )
qusgrp2.p	|- ( ph -> .+ = ( +g ` R ) )
qusgrp2.r	|- ( ph -> .~ Er V )
qusgrp2.x	|- ( ph -> R e. X )
qusgrp2.e	|- ( ph -> ( ( a .~ p /\ b .~ q ) -> ( a .+ b ) .~ ( p .+ q ) ) )
qusgrp2.1	|- ( ( ph /\ x e. V /\ y e. V ) -> ( x .+ y ) e. V )
qusgrp2.2	|- ( ( ph /\ ( x e. V /\ y e. V /\ z e. V ) ) -> ( ( x .+ y ) .+ z ) .~ ( x .+ ( y .+ z ) ) )
qusgrp2.3	|- ( ph -> .0. e. V )
qusgrp2.4	|- ( ( ph /\ x e. V ) -> ( .0. .+ x ) .~ x )
qusgrp2.5	|- ( ( ph /\ x e. V ) -> N e. V )
qusgrp2.6	|- ( ( ph /\ x e. V ) -> ( N .+ x ) .~ .0. )

Assertion

Ref	Expression
qusgrp2	|- ( ph -> ( U e. Grp /\ [ .0. ] .~ = ( 0g ` U ) ) )

Distinct variable groups:   a, b, p, q, x, y, z, .~   .0. , a, b, p, q, x   N, p   R, p, q   .+ , a, b, p, q, x, y   ph, a, b, p, q, x, y, z   V, a, b, p, q, x, y, z   U, a, b, p, q, x, y, z

Allowed substitution hints:   .+ ( z)   R( x, y, z, a, b)   N( x, y, z, q, a, b)   X( x, y, z, q, p, a, b)   .0. ( y, z)

Proof of Theorem qusgrp2

Dummy variable u is distinct from all other variables.

Step	Hyp	Ref	Expression
1		qusgrp2.u	. . . 4 |- ( ph -> U = ( R /.s .~ ) )
2		qusgrp2.v	. . . 4 |- ( ph -> V = ( Base ` R ) )
3		eqid 2622	. . . 4 |- ( u e. V |-> [ u ] .~ ) = ( u e. V |-> [ u ] .~ )
4		qusgrp2.r	. . . . 5 |- ( ph -> .~ Er V )
5		fvex 6201	. . . . . 6 |- ( Base ` R ) e. _V
6	2, 5	syl6eqel 2709	. . . . 5 |- ( ph -> V e. _V )
7		erex 7766	. . . . 5 |- ( .~ Er V -> ( V e. _V -> .~ e. _V ) )
8	4, 6, 7	sylc 65	. . . 4 |- ( ph -> .~ e. _V )
9		qusgrp2.x	. . . 4 |- ( ph -> R e. X )
10	1, 2, 3, 8, 9	qusval 16202	. . 3 |- ( ph -> U = ( ( u e. V |-> [ u ] .~ ) "s R ) )
11		qusgrp2.p	. . 3 |- ( ph -> .+ = ( +g ` R ) )
12	1, 2, 3, 8, 9	quslem 16203	. . 3 |- ( ph -> ( u e. V |-> [ u ] .~ ) : V -onto-> ( V /. .~ ) )
13		qusgrp2.1	. . . . 5 |- ( ( ph /\ x e. V /\ y e. V ) -> ( x .+ y ) e. V )
14	13	3expb 1266	. . . 4 |- ( ( ph /\ ( x e. V /\ y e. V ) ) -> ( x .+ y ) e. V )
15		qusgrp2.e	. . . 4 |- ( ph -> ( ( a .~ p /\ b .~ q ) -> ( a .+ b ) .~ ( p .+ q ) ) )
16	4, 6, 3, 14, 15	ercpbl 16209	. . 3 |- ( ( ph /\ ( a e. V /\ b e. V ) /\ ( p e. V /\ q e. V ) ) -> ( ( ( ( u e. V |-> [ u ] .~ ) ` a ) = ( ( u e. V |-> [ u ] .~ ) ` p ) /\ ( ( u e. V |-> [ u ] .~ ) ` b ) = ( ( u e. V |-> [ u ] .~ ) ` q ) ) -> ( ( u e. V |-> [ u ] .~ ) ` ( a .+ b ) ) = ( ( u e. V |-> [ u ] .~ ) ` ( p .+ q ) ) ) )
17	4	adantr 481	. . . . 5 |- ( ( ph /\ ( x e. V /\ y e. V /\ z e. V ) ) -> .~ Er V )
18		qusgrp2.2	. . . . 5 |- ( ( ph /\ ( x e. V /\ y e. V /\ z e. V ) ) -> ( ( x .+ y ) .+ z ) .~ ( x .+ ( y .+ z ) ) )
19	17, 18	erthi 7793	. . . 4 |- ( ( ph /\ ( x e. V /\ y e. V /\ z e. V ) ) -> [ ( ( x .+ y ) .+ z ) ] .~ = [ ( x .+ ( y .+ z ) ) ] .~ )
20	6	adantr 481	. . . . 5 |- ( ( ph /\ ( x e. V /\ y e. V /\ z e. V ) ) -> V e. _V )
21	17, 20, 3	divsfval 16207	. . . 4 |- ( ( ph /\ ( x e. V /\ y e. V /\ z e. V ) ) -> ( ( u e. V |-> [ u ] .~ ) ` ( ( x .+ y ) .+ z ) ) = [ ( ( x .+ y ) .+ z ) ] .~ )
22	17, 20, 3	divsfval 16207	. . . 4 |- ( ( ph /\ ( x e. V /\ y e. V /\ z e. V ) ) -> ( ( u e. V |-> [ u ] .~ ) ` ( x .+ ( y .+ z ) ) ) = [ ( x .+ ( y .+ z ) ) ] .~ )
23	19, 21, 22	3eqtr4d 2666	. . 3 |- ( ( ph /\ ( x e. V /\ y e. V /\ z e. V ) ) -> ( ( u e. V |-> [ u ] .~ ) ` ( ( x .+ y ) .+ z ) ) = ( ( u e. V |-> [ u ] .~ ) ` ( x .+ ( y .+ z ) ) ) )
24		qusgrp2.3	. . 3 |- ( ph -> .0. e. V )
25	4	adantr 481	. . . . 5 |- ( ( ph /\ x e. V ) -> .~ Er V )
26		qusgrp2.4	. . . . 5 |- ( ( ph /\ x e. V ) -> ( .0. .+ x ) .~ x )
27	25, 26	erthi 7793	. . . 4 |- ( ( ph /\ x e. V ) -> [ ( .0. .+ x ) ] .~ = [ x ] .~ )
28	6	adantr 481	. . . . 5 |- ( ( ph /\ x e. V ) -> V e. _V )
29	25, 28, 3	divsfval 16207	. . . 4 |- ( ( ph /\ x e. V ) -> ( ( u e. V |-> [ u ] .~ ) ` ( .0. .+ x ) ) = [ ( .0. .+ x ) ] .~ )
30	25, 28, 3	divsfval 16207	. . . 4 |- ( ( ph /\ x e. V ) -> ( ( u e. V |-> [ u ] .~ ) ` x ) = [ x ] .~ )
31	27, 29, 30	3eqtr4d 2666	. . 3 |- ( ( ph /\ x e. V ) -> ( ( u e. V |-> [ u ] .~ ) ` ( .0. .+ x ) ) = ( ( u e. V |-> [ u ] .~ ) ` x ) )
32		qusgrp2.5	. . 3 |- ( ( ph /\ x e. V ) -> N e. V )
33		qusgrp2.6	. . . . . 6 |- ( ( ph /\ x e. V ) -> ( N .+ x ) .~ .0. )
34	25, 33	ersym 7754	. . . . 5 |- ( ( ph /\ x e. V ) -> .0. .~ ( N .+ x ) )
35	25, 34	erthi 7793	. . . 4 |- ( ( ph /\ x e. V ) -> [ .0. ] .~ = [ ( N .+ x ) ] .~ )
36	25, 28, 3	divsfval 16207	. . . 4 |- ( ( ph /\ x e. V ) -> ( ( u e. V |-> [ u ] .~ ) ` .0. ) = [ .0. ] .~ )
37	25, 28, 3	divsfval 16207	. . . 4 |- ( ( ph /\ x e. V ) -> ( ( u e. V |-> [ u ] .~ ) ` ( N .+ x ) ) = [ ( N .+ x ) ] .~ )
38	35, 36, 37	3eqtr4rd 2667	. . 3 |- ( ( ph /\ x e. V ) -> ( ( u e. V |-> [ u ] .~ ) ` ( N .+ x ) ) = ( ( u e. V |-> [ u ] .~ ) ` .0. ) )
39	10, 2, 11, 12, 16, 9, 13, 23, 24, 31, 32, 38	imasgrp2 17530	. 2 |- ( ph -> ( U e. Grp /\ ( ( u e. V |-> [ u ] .~ ) ` .0. ) = ( 0g ` U ) ) )
40	4, 6, 3	divsfval 16207	. . . . 5 |- ( ph -> ( ( u e. V |-> [ u ] .~ ) ` .0. ) = [ .0. ] .~ )
41	40	eqcomd 2628	. . . 4 |- ( ph -> [ .0. ] .~ = ( ( u e. V |-> [ u ] .~ ) ` .0. ) )
42	41	eqeq1d 2624	. . 3 |- ( ph -> ( [ .0. ] .~ = ( 0g ` U ) <-> ( ( u e. V |-> [ u ] .~ ) ` .0. ) = ( 0g ` U ) ) )
43	42	anbi2d 740	. 2 |- ( ph -> ( ( U e. Grp /\ [ .0. ] .~ = ( 0g ` U ) ) <-> ( U e. Grp /\ ( ( u e. V |-> [ u ] .~ ) ` .0. ) = ( 0g ` U ) ) ) )
44	39, 43	mpbird 247	1 |- ( ph -> ( U e. Grp /\ [ .0. ] .~ = ( 0g ` U ) ) )

Syntax hints:   -> wi 4   /\ wa 384   /\ w3a 1037   = wceq 1483   e. wcel 1990   _Vcvv 3200   class class class wbr 4653   |-> cmpt 4729   ` cfv 5888  (class class class)co 6650   Er wer 7739   [cec 7740   /.cqs 7741   Basecbs 15857   +g cplusg 15941   0gc0g 16100   /._s cqus 16165   Grpcgrp 17422

This theorem was proved from axioms:  ax-mp 5  ax-1 6  ax-2 7  ax-3 8  ax-gen 1722  ax-4 1737  ax-5 1839  ax-6 1888  ax-7 1935  ax-8 1992  ax-9 1999  ax-10 2019  ax-11 2034  ax-12 2047  ax-13 2246  ax-ext 2602  ax-rep 4771  ax-sep 4781  ax-nul 4789  ax-pow 4843  ax-pr 4906  ax-un 6949  ax-cnex 9992  ax-resscn 9993  ax-1cn 9994  ax-icn 9995  ax-addcl 9996  ax-addrcl 9997  ax-mulcl 9998  ax-mulrcl 9999  ax-mulcom 10000  ax-addass 10001  ax-mulass 10002  ax-distr 10003  ax-i2m1 10004  ax-1ne0 10005  ax-1rid 10006  ax-rnegex 10007  ax-rrecex 10008  ax-cnre 10009  ax-pre-lttri 10010  ax-pre-lttrn 10011  ax-pre-ltadd 10012  ax-pre-mulgt0 10013

This theorem depends on definitions:  df-bi 197  df-or 385  df-an 386  df-3or 1038  df-3an 1039  df-tru 1486  df-ex 1705  df-nf 1710  df-sb 1881  df-eu 2474  df-mo 2475  df-clab 2609  df-cleq 2615  df-clel 2618  df-nfc 2753  df-ne 2795  df-nel 2898  df-ral 2917  df-rex 2918  df-reu 2919  df-rmo 2920  df-rab 2921  df-v 3202  df-sbc 3436  df-csb 3534  df-dif 3577  df-un 3579  df-in 3581  df-ss 3588  df-pss 3590  df-nul 3916  df-if 4087  df-pw 4160  df-sn 4178  df-pr 4180  df-tp 4182  df-op 4184  df-uni 4437  df-int 4476  df-iun 4522  df-br 4654  df-opab 4713  df-mpt 4730  df-tr 4753  df-id 5024  df-eprel 5029  df-po 5035  df-so 5036  df-fr 5073  df-we 5075  df-xp 5120  df-rel 5121  df-cnv 5122  df-co 5123  df-dm 5124  df-rn 5125  df-res 5126  df-ima 5127  df-pred 5680  df-ord 5726  df-on 5727  df-lim 5728  df-suc 5729  df-iota 5851  df-fun 5890  df-fn 5891  df-f 5892  df-f1 5893  df-fo 5894  df-f1o 5895  df-fv 5896  df-riota 6611  df-ov 6653  df-oprab 6654  df-mpt2 6655  df-om 7066  df-1st 7168  df-2nd 7169  df-wrecs 7407  df-recs 7468  df-rdg 7506  df-1o 7560  df-oadd 7564  df-er 7742  df-ec 7744  df-qs 7748  df-en 7956  df-dom 7957  df-sdom 7958  df-fin 7959  df-sup 8348  df-inf 8349  df-pnf 10076  df-mnf 10077  df-xr 10078  df-ltxr 10079  df-le 10080  df-sub 10268  df-neg 10269  df-nn 11021  df-2 11079  df-3 11080  df-4 11081  df-5 11082  df-6 11083  df-7 11084  df-8 11085  df-9 11086  df-n0 11293  df-z 11378  df-dec 11494  df-uz 11688  df-fz 12327  df-struct 15859  df-ndx 15860  df-slot 15861  df-base 15863  df-plusg 15954  df-mulr 15955  df-sca 15957  df-vsca 15958  df-ip 15959  df-tset 15960  df-ple 15961  df-ds 15964  df-0g 16102  df-imas 16168  df-qus 16169  df-mgm 17242  df-sgrp 17284  df-mnd 17295  df-grp 17425

This theorem is referenced by:  qusgrp  17649  frgp0  18173  pi1grplem  22849