Theorem isoval 16425

Description: The isomorphisms are the domain of the inverse relation. (Contributed by Mario Carneiro, 2-Jan-2017.) (Proof shortened by AV, 21-May-2020.)

Hypotheses

Ref	Expression
invfval.b	|- B = ( Base ` C )
invfval.n	|- N = (Inv ` C )
invfval.c	|- ( ph -> C e. Cat )
invfval.x	|- ( ph -> X e. B )
invfval.y	|- ( ph -> Y e. B )
isoval.n	|- I = ( Iso ` C )

Assertion

Ref	Expression
isoval	|- ( ph -> ( X I Y ) = dom ( X N Y ) )

Proof of Theorem isoval

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

Step	Hyp	Ref	Expression
1		invfval.c	. . . . 5 |- ( ph -> C e. Cat )
2		isofval 16417	. . . . 5 |- ( C e. Cat -> ( Iso ` C ) = ( ( z e. _V |-> dom z ) o. (Inv ` C ) ) )
3	1, 2	syl 17	. . . 4 |- ( ph -> ( Iso ` C ) = ( ( z e. _V |-> dom z ) o. (Inv ` C ) ) )
4		isoval.n	. . . 4 |- I = ( Iso ` C )
5		invfval.n	. . . . 5 |- N = (Inv ` C )
6	5	coeq2i 5282	. . . 4 |- ( ( z e. _V |-> dom z ) o. N ) = ( ( z e. _V |-> dom z ) o. (Inv ` C ) )
7	3, 4, 6	3eqtr4g 2681	. . 3 |- ( ph -> I = ( ( z e. _V |-> dom z ) o. N ) )
8	7	oveqd 6667	. 2 |- ( ph -> ( X I Y ) = ( X ( ( z e. _V |-> dom z ) o. N ) Y ) )
9		eqid 2622	. . . . . 6 |- ( x e. B , y e. B |-> ( ( x (Sect ` C ) y ) i^i `' ( y (Sect ` C ) x ) ) ) = ( x e. B , y e. B |-> ( ( x (Sect ` C ) y ) i^i `' ( y (Sect ` C ) x ) ) )
10		ovex 6678	. . . . . . 7 |- ( x (Sect ` C ) y ) e. _V
11	10	inex1 4799	. . . . . 6 |- ( ( x (Sect ` C ) y ) i^i `' ( y (Sect ` C ) x ) ) e. _V
12	9, 11	fnmpt2i 7239	. . . . 5 |- ( x e. B , y e. B |-> ( ( x (Sect ` C ) y ) i^i `' ( y (Sect ` C ) x ) ) ) Fn ( B X. B )
13		invfval.b	. . . . . . 7 |- B = ( Base ` C )
14		invfval.x	. . . . . . 7 |- ( ph -> X e. B )
15		invfval.y	. . . . . . 7 |- ( ph -> Y e. B )
16		eqid 2622	. . . . . . 7 |- (Sect ` C ) = (Sect ` C )
17	13, 5, 1, 14, 15, 16	invffval 16418	. . . . . 6 |- ( ph -> N = ( x e. B , y e. B |-> ( ( x (Sect ` C ) y ) i^i `' ( y (Sect ` C ) x ) ) ) )
18	17	fneq1d 5981	. . . . 5 |- ( ph -> ( N Fn ( B X. B ) <-> ( x e. B , y e. B |-> ( ( x (Sect ` C ) y ) i^i `' ( y (Sect ` C ) x ) ) ) Fn ( B X. B ) ) )
19	12, 18	mpbiri 248	. . . 4 |- ( ph -> N Fn ( B X. B ) )
20		opelxpi 5148	. . . . 5 |- ( ( X e. B /\ Y e. B ) -> <. X , Y >. e. ( B X. B ) )
21	14, 15, 20	syl2anc 693	. . . 4 |- ( ph -> <. X , Y >. e. ( B X. B ) )
22		fvco2 6273	. . . 4 |- ( ( N Fn ( B X. B ) /\ <. X , Y >. e. ( B X. B ) ) -> ( ( ( z e. _V |-> dom z ) o. N ) ` <. X , Y >. ) = ( ( z e. _V |-> dom z ) ` ( N ` <. X , Y >. ) ) )
23	19, 21, 22	syl2anc 693	. . 3 |- ( ph -> ( ( ( z e. _V |-> dom z ) o. N ) ` <. X , Y >. ) = ( ( z e. _V |-> dom z ) ` ( N ` <. X , Y >. ) ) )
24		df-ov 6653	. . 3 |- ( X ( ( z e. _V |-> dom z ) o. N ) Y ) = ( ( ( z e. _V |-> dom z ) o. N ) ` <. X , Y >. )
25		ovex 6678	. . . . 5 |- ( X N Y ) e. _V
26		dmeq 5324	. . . . . 6 |- ( z = ( X N Y ) -> dom z = dom ( X N Y ) )
27		eqid 2622	. . . . . 6 |- ( z e. _V |-> dom z ) = ( z e. _V |-> dom z )
28	25	dmex 7099	. . . . . 6 |- dom ( X N Y ) e. _V
29	26, 27, 28	fvmpt 6282	. . . . 5 |- ( ( X N Y ) e. _V -> ( ( z e. _V |-> dom z ) ` ( X N Y ) ) = dom ( X N Y ) )
30	25, 29	ax-mp 5	. . . 4 |- ( ( z e. _V |-> dom z ) ` ( X N Y ) ) = dom ( X N Y )
31		df-ov 6653	. . . . 5 |- ( X N Y ) = ( N ` <. X , Y >. )
32	31	fveq2i 6194	. . . 4 |- ( ( z e. _V |-> dom z ) ` ( X N Y ) ) = ( ( z e. _V |-> dom z ) ` ( N ` <. X , Y >. ) )
33	30, 32	eqtr3i 2646	. . 3 |- dom ( X N Y ) = ( ( z e. _V |-> dom z ) ` ( N ` <. X , Y >. ) )
34	23, 24, 33	3eqtr4g 2681	. 2 |- ( ph -> ( X ( ( z e. _V |-> dom z ) o. N ) Y ) = dom ( X N Y ) )
35	8, 34	eqtrd 2656	1 |- ( ph -> ( X I Y ) = dom ( X N Y ) )

Syntax hints:   -> wi 4   = wceq 1483   e. wcel 1990   _Vcvv 3200   i^i cin 3573   <.cop 4183   |-> cmpt 4729   X. cxp 5112   `'ccnv 5113   dom cdm 5114   o. ccom 5118   Fn wfn 5883   ` cfv 5888  (class class class)co 6650   |-> cmpt2 6652   Basecbs 15857   Catccat 16325  Sectcsect 16404  Invcinv 16405   Iso ciso 16406

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

This theorem depends on definitions:  df-bi 197  df-or 385  df-an 386  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-ral 2917  df-rex 2918  df-reu 2919  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-nul 3916  df-if 4087  df-pw 4160  df-sn 4178  df-pr 4180  df-op 4184  df-uni 4437  df-iun 4522  df-br 4654  df-opab 4713  df-mpt 4730  df-id 5024  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-iota 5851  df-fun 5890  df-fn 5891  df-f 5892  df-f1 5893  df-fo 5894  df-f1o 5895  df-fv 5896  df-ov 6653  df-oprab 6654  df-mpt2 6655  df-1st 7168  df-2nd 7169  df-inv 16408  df-iso 16409

This theorem is referenced by:  inviso1  16426  invf  16428  invco  16431  dfiso2  16432  isohom  16436  oppciso  16441  cicsym  16464  funciso  16534  ffthiso  16589  fuciso  16635  setciso  16741  catciso  16757  rngciso  41982  rngcisoALTV  41994  ringciso  42033  ringcisoALTV  42057