| Step |
Hyp |
Ref |
Expression |
| 1 |
|
caovdir2d.1 |
|- ( ( ph /\ ( x e. S /\ y e. S /\ z e. S ) ) -> ( x G ( y F z ) ) = ( ( x G y ) F ( x G z ) ) ) |
| 2 |
|
caovdir2d.2 |
|- ( ph -> A e. S ) |
| 3 |
|
caovdir2d.3 |
|- ( ph -> B e. S ) |
| 4 |
|
caovdir2d.4 |
|- ( ph -> C e. S ) |
| 5 |
|
caovdir2d.cl |
|- ( ( ph /\ ( x e. S /\ y e. S ) ) -> ( x F y ) e. S ) |
| 6 |
|
caovdir2d.com |
|- ( ( ph /\ ( x e. S /\ y e. S ) ) -> ( x G y ) = ( y G x ) ) |
| 7 |
1 4 2 3
|
caovdid |
|- ( ph -> ( C G ( A F B ) ) = ( ( C G A ) F ( C G B ) ) ) |
| 8 |
5 2 3
|
caovcld |
|- ( ph -> ( A F B ) e. S ) |
| 9 |
6 8 4
|
caovcomd |
|- ( ph -> ( ( A F B ) G C ) = ( C G ( A F B ) ) ) |
| 10 |
6 2 4
|
caovcomd |
|- ( ph -> ( A G C ) = ( C G A ) ) |
| 11 |
6 3 4
|
caovcomd |
|- ( ph -> ( B G C ) = ( C G B ) ) |
| 12 |
10 11
|
oveq12d |
|- ( ph -> ( ( A G C ) F ( B G C ) ) = ( ( C G A ) F ( C G B ) ) ) |
| 13 |
7 9 12
|
3eqtr4d |
|- ( ph -> ( ( A F B ) G C ) = ( ( A G C ) F ( B G C ) ) ) |