| Step |
Hyp |
Ref |
Expression |
| 1 |
|
drnginvmuld.b |
|- B = ( Base ` R ) |
| 2 |
|
drnginvmuld.z |
|- .0. = ( 0g ` R ) |
| 3 |
|
drnginvmuld.t |
|- .x. = ( .r ` R ) |
| 4 |
|
drnginvmuld.i |
|- I = ( invr ` R ) |
| 5 |
|
drnginvmuld.r |
|- ( ph -> R e. DivRing ) |
| 6 |
|
drnginvmuld.x |
|- ( ph -> X e. B ) |
| 7 |
|
drnginvmuld.y |
|- ( ph -> Y e. B ) |
| 8 |
|
drnginvmuld.1 |
|- ( ph -> X =/= .0. ) |
| 9 |
|
drnginvmuld.2 |
|- ( ph -> Y =/= .0. ) |
| 10 |
5
|
drngringd |
|- ( ph -> R e. Ring ) |
| 11 |
1 3 10 6 7
|
ringcld |
|- ( ph -> ( X .x. Y ) e. B ) |
| 12 |
1 2 3 5 6 7
|
drngmulne0 |
|- ( ph -> ( ( X .x. Y ) =/= .0. <-> ( X =/= .0. /\ Y =/= .0. ) ) ) |
| 13 |
8 9 12
|
mpbir2and |
|- ( ph -> ( X .x. Y ) =/= .0. ) |
| 14 |
1 2 4 5 11 13
|
drnginvrcld |
|- ( ph -> ( I ` ( X .x. Y ) ) e. B ) |
| 15 |
1 2 4 5 7 9
|
drnginvrcld |
|- ( ph -> ( I ` Y ) e. B ) |
| 16 |
1 2 4 5 6 8
|
drnginvrcld |
|- ( ph -> ( I ` X ) e. B ) |
| 17 |
1 3 10 15 16
|
ringcld |
|- ( ph -> ( ( I ` Y ) .x. ( I ` X ) ) e. B ) |
| 18 |
|
eqid |
|- ( 1r ` R ) = ( 1r ` R ) |
| 19 |
1 2 3 18 4 5 6 8
|
drnginvrld |
|- ( ph -> ( ( I ` X ) .x. X ) = ( 1r ` R ) ) |
| 20 |
19
|
oveq1d |
|- ( ph -> ( ( ( I ` X ) .x. X ) .x. Y ) = ( ( 1r ` R ) .x. Y ) ) |
| 21 |
1 3 18 10 7
|
ringlidmd |
|- ( ph -> ( ( 1r ` R ) .x. Y ) = Y ) |
| 22 |
20 21
|
eqtrd |
|- ( ph -> ( ( ( I ` X ) .x. X ) .x. Y ) = Y ) |
| 23 |
22
|
oveq2d |
|- ( ph -> ( ( I ` Y ) .x. ( ( ( I ` X ) .x. X ) .x. Y ) ) = ( ( I ` Y ) .x. Y ) ) |
| 24 |
23
|
eqcomd |
|- ( ph -> ( ( I ` Y ) .x. Y ) = ( ( I ` Y ) .x. ( ( ( I ` X ) .x. X ) .x. Y ) ) ) |
| 25 |
1 2 3 18 4 5 7 9
|
drnginvrld |
|- ( ph -> ( ( I ` Y ) .x. Y ) = ( 1r ` R ) ) |
| 26 |
1 3 10 16 6 7
|
ringassd |
|- ( ph -> ( ( ( I ` X ) .x. X ) .x. Y ) = ( ( I ` X ) .x. ( X .x. Y ) ) ) |
| 27 |
26
|
oveq2d |
|- ( ph -> ( ( I ` Y ) .x. ( ( ( I ` X ) .x. X ) .x. Y ) ) = ( ( I ` Y ) .x. ( ( I ` X ) .x. ( X .x. Y ) ) ) ) |
| 28 |
24 25 27
|
3eqtr3d |
|- ( ph -> ( 1r ` R ) = ( ( I ` Y ) .x. ( ( I ` X ) .x. ( X .x. Y ) ) ) ) |
| 29 |
1 2 3 18 4 5 11 13
|
drnginvrld |
|- ( ph -> ( ( I ` ( X .x. Y ) ) .x. ( X .x. Y ) ) = ( 1r ` R ) ) |
| 30 |
1 3 10 15 16 11
|
ringassd |
|- ( ph -> ( ( ( I ` Y ) .x. ( I ` X ) ) .x. ( X .x. Y ) ) = ( ( I ` Y ) .x. ( ( I ` X ) .x. ( X .x. Y ) ) ) ) |
| 31 |
28 29 30
|
3eqtr4d |
|- ( ph -> ( ( I ` ( X .x. Y ) ) .x. ( X .x. Y ) ) = ( ( ( I ` Y ) .x. ( I ` X ) ) .x. ( X .x. Y ) ) ) |
| 32 |
1 2 3 5 14 17 11 13 31
|
drngmulrcan |
|- ( ph -> ( I ` ( X .x. Y ) ) = ( ( I ` Y ) .x. ( I ` X ) ) ) |