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