| Step |
Hyp |
Ref |
Expression |
| 1 |
|
caovass.1 |
|- A e. _V |
| 2 |
|
caovass.2 |
|- B e. _V |
| 3 |
|
caovass.3 |
|- C e. _V |
| 4 |
|
caovass.4 |
|- ( ( x F y ) F z ) = ( x F ( y F z ) ) |
| 5 |
|
tru |
|- T. |
| 6 |
4
|
a1i |
|- ( ( T. /\ ( x e. _V /\ y e. _V /\ z e. _V ) ) -> ( ( x F y ) F z ) = ( x F ( y F z ) ) ) |
| 7 |
6
|
caovassg |
|- ( ( T. /\ ( A e. _V /\ B e. _V /\ C e. _V ) ) -> ( ( A F B ) F C ) = ( A F ( B F C ) ) ) |
| 8 |
5 7
|
mpan |
|- ( ( A e. _V /\ B e. _V /\ C e. _V ) -> ( ( A F B ) F C ) = ( A F ( B F C ) ) ) |
| 9 |
1 2 3 8
|
mp3an |
|- ( ( A F B ) F C ) = ( A F ( B F C ) ) |