Step |
Hyp |
Ref |
Expression |
1 |
|
xpsinv.t |
|- T = ( R Xs. S ) |
2 |
|
xpsinv.x |
|- X = ( Base ` R ) |
3 |
|
xpsinv.y |
|- Y = ( Base ` S ) |
4 |
|
xpsinv.r |
|- ( ph -> R e. Grp ) |
5 |
|
xpsinv.s |
|- ( ph -> S e. Grp ) |
6 |
|
xpsinv.a |
|- ( ph -> A e. X ) |
7 |
|
xpsinv.b |
|- ( ph -> B e. Y ) |
8 |
|
xpsinv.m |
|- M = ( invg ` R ) |
9 |
|
xpsinv.n |
|- N = ( invg ` S ) |
10 |
|
xpsinv.i |
|- I = ( invg ` T ) |
11 |
|
eqid |
|- ( +g ` R ) = ( +g ` R ) |
12 |
|
eqid |
|- ( 0g ` R ) = ( 0g ` R ) |
13 |
2 11 12 8 4 6
|
grplinvd |
|- ( ph -> ( ( M ` A ) ( +g ` R ) A ) = ( 0g ` R ) ) |
14 |
|
eqid |
|- ( +g ` S ) = ( +g ` S ) |
15 |
|
eqid |
|- ( 0g ` S ) = ( 0g ` S ) |
16 |
3 14 15 9 5 7
|
grplinvd |
|- ( ph -> ( ( N ` B ) ( +g ` S ) B ) = ( 0g ` S ) ) |
17 |
13 16
|
opeq12d |
|- ( ph -> <. ( ( M ` A ) ( +g ` R ) A ) , ( ( N ` B ) ( +g ` S ) B ) >. = <. ( 0g ` R ) , ( 0g ` S ) >. ) |
18 |
2 8 4 6
|
grpinvcld |
|- ( ph -> ( M ` A ) e. X ) |
19 |
3 9 5 7
|
grpinvcld |
|- ( ph -> ( N ` B ) e. Y ) |
20 |
2 11 4 18 6
|
grpcld |
|- ( ph -> ( ( M ` A ) ( +g ` R ) A ) e. X ) |
21 |
3 14 5 19 7
|
grpcld |
|- ( ph -> ( ( N ` B ) ( +g ` S ) B ) e. Y ) |
22 |
|
eqid |
|- ( +g ` T ) = ( +g ` T ) |
23 |
1 2 3 4 5 18 19 6 7 20 21 11 14 22
|
xpsadd |
|- ( ph -> ( <. ( M ` A ) , ( N ` B ) >. ( +g ` T ) <. A , B >. ) = <. ( ( M ` A ) ( +g ` R ) A ) , ( ( N ` B ) ( +g ` S ) B ) >. ) |
24 |
4
|
grpmndd |
|- ( ph -> R e. Mnd ) |
25 |
5
|
grpmndd |
|- ( ph -> S e. Mnd ) |
26 |
1
|
xpsmnd0 |
|- ( ( R e. Mnd /\ S e. Mnd ) -> ( 0g ` T ) = <. ( 0g ` R ) , ( 0g ` S ) >. ) |
27 |
24 25 26
|
syl2anc |
|- ( ph -> ( 0g ` T ) = <. ( 0g ` R ) , ( 0g ` S ) >. ) |
28 |
17 23 27
|
3eqtr4d |
|- ( ph -> ( <. ( M ` A ) , ( N ` B ) >. ( +g ` T ) <. A , B >. ) = ( 0g ` T ) ) |
29 |
1
|
xpsgrp |
|- ( ( R e. Grp /\ S e. Grp ) -> T e. Grp ) |
30 |
4 5 29
|
syl2anc |
|- ( ph -> T e. Grp ) |
31 |
6 7
|
opelxpd |
|- ( ph -> <. A , B >. e. ( X X. Y ) ) |
32 |
1 2 3 4 5
|
xpsbas |
|- ( ph -> ( X X. Y ) = ( Base ` T ) ) |
33 |
31 32
|
eleqtrd |
|- ( ph -> <. A , B >. e. ( Base ` T ) ) |
34 |
18 19
|
opelxpd |
|- ( ph -> <. ( M ` A ) , ( N ` B ) >. e. ( X X. Y ) ) |
35 |
34 32
|
eleqtrd |
|- ( ph -> <. ( M ` A ) , ( N ` B ) >. e. ( Base ` T ) ) |
36 |
|
eqid |
|- ( Base ` T ) = ( Base ` T ) |
37 |
|
eqid |
|- ( 0g ` T ) = ( 0g ` T ) |
38 |
36 22 37 10
|
grpinvid2 |
|- ( ( T e. Grp /\ <. A , B >. e. ( Base ` T ) /\ <. ( M ` A ) , ( N ` B ) >. e. ( Base ` T ) ) -> ( ( I ` <. A , B >. ) = <. ( M ` A ) , ( N ` B ) >. <-> ( <. ( M ` A ) , ( N ` B ) >. ( +g ` T ) <. A , B >. ) = ( 0g ` T ) ) ) |
39 |
30 33 35 38
|
syl3anc |
|- ( ph -> ( ( I ` <. A , B >. ) = <. ( M ` A ) , ( N ` B ) >. <-> ( <. ( M ` A ) , ( N ` B ) >. ( +g ` T ) <. A , B >. ) = ( 0g ` T ) ) ) |
40 |
28 39
|
mpbird |
|- ( ph -> ( I ` <. A , B >. ) = <. ( M ` A ) , ( N ` B ) >. ) |