Step |
Hyp |
Ref |
Expression |
1 |
|
caovd.1 |
|- ( ph -> A e. S ) |
2 |
|
caovd.2 |
|- ( ph -> B e. S ) |
3 |
|
caovd.3 |
|- ( ph -> C e. S ) |
4 |
|
caovd.com |
|- ( ( ph /\ ( x e. S /\ y e. S ) ) -> ( x F y ) = ( y F x ) ) |
5 |
|
caovd.ass |
|- ( ( ph /\ ( x e. S /\ y e. S /\ z e. S ) ) -> ( ( x F y ) F z ) = ( x F ( y F z ) ) ) |
6 |
|
caovd.4 |
|- ( ph -> D e. S ) |
7 |
|
caovd.cl |
|- ( ( ph /\ ( x e. S /\ y e. S ) ) -> ( x F y ) e. S ) |
8 |
2 1 3 4 5 6 7
|
caov4d |
|- ( ph -> ( ( B F A ) F ( C F D ) ) = ( ( B F C ) F ( A F D ) ) ) |
9 |
4 2 1
|
caovcomd |
|- ( ph -> ( B F A ) = ( A F B ) ) |
10 |
9
|
oveq1d |
|- ( ph -> ( ( B F A ) F ( C F D ) ) = ( ( A F B ) F ( C F D ) ) ) |
11 |
4 2 3
|
caovcomd |
|- ( ph -> ( B F C ) = ( C F B ) ) |
12 |
11
|
oveq1d |
|- ( ph -> ( ( B F C ) F ( A F D ) ) = ( ( C F B ) F ( A F D ) ) ) |
13 |
8 10 12
|
3eqtr3d |
|- ( ph -> ( ( A F B ) F ( C F D ) ) = ( ( C F B ) F ( A F D ) ) ) |