| Step | Hyp | Ref | Expression | 
						
							| 1 |  | abldiv.1 |  |-  X = ran G | 
						
							| 2 |  | abldiv.3 |  |-  D = ( /g ` G ) | 
						
							| 3 | 1 | ablocom |  |-  ( ( G e. AbelOp /\ A e. X /\ B e. X ) -> ( A G B ) = ( B G A ) ) | 
						
							| 4 | 3 | 3adant3r3 |  |-  ( ( G e. AbelOp /\ ( A e. X /\ B e. X /\ C e. X ) ) -> ( A G B ) = ( B G A ) ) | 
						
							| 5 | 4 | oveq1d |  |-  ( ( G e. AbelOp /\ ( A e. X /\ B e. X /\ C e. X ) ) -> ( ( A G B ) D C ) = ( ( B G A ) D C ) ) | 
						
							| 6 |  | 3ancoma |  |-  ( ( A e. X /\ B e. X /\ C e. X ) <-> ( B e. X /\ A e. X /\ C e. X ) ) | 
						
							| 7 |  | ablogrpo |  |-  ( G e. AbelOp -> G e. GrpOp ) | 
						
							| 8 | 1 2 | grpomuldivass |  |-  ( ( G e. GrpOp /\ ( B e. X /\ A e. X /\ C e. X ) ) -> ( ( B G A ) D C ) = ( B G ( A D C ) ) ) | 
						
							| 9 | 7 8 | sylan |  |-  ( ( G e. AbelOp /\ ( B e. X /\ A e. X /\ C e. X ) ) -> ( ( B G A ) D C ) = ( B G ( A D C ) ) ) | 
						
							| 10 | 6 9 | sylan2b |  |-  ( ( G e. AbelOp /\ ( A e. X /\ B e. X /\ C e. X ) ) -> ( ( B G A ) D C ) = ( B G ( A D C ) ) ) | 
						
							| 11 |  | simpr2 |  |-  ( ( G e. AbelOp /\ ( A e. X /\ B e. X /\ C e. X ) ) -> B e. X ) | 
						
							| 12 | 1 2 | grpodivcl |  |-  ( ( G e. GrpOp /\ A e. X /\ C e. X ) -> ( A D C ) e. X ) | 
						
							| 13 | 7 12 | syl3an1 |  |-  ( ( G e. AbelOp /\ A e. X /\ C e. X ) -> ( A D C ) e. X ) | 
						
							| 14 | 13 | 3adant3r2 |  |-  ( ( G e. AbelOp /\ ( A e. X /\ B e. X /\ C e. X ) ) -> ( A D C ) e. X ) | 
						
							| 15 | 11 14 | jca |  |-  ( ( G e. AbelOp /\ ( A e. X /\ B e. X /\ C e. X ) ) -> ( B e. X /\ ( A D C ) e. X ) ) | 
						
							| 16 | 1 | ablocom |  |-  ( ( G e. AbelOp /\ B e. X /\ ( A D C ) e. X ) -> ( B G ( A D C ) ) = ( ( A D C ) G B ) ) | 
						
							| 17 | 16 | 3expb |  |-  ( ( G e. AbelOp /\ ( B e. X /\ ( A D C ) e. X ) ) -> ( B G ( A D C ) ) = ( ( A D C ) G B ) ) | 
						
							| 18 | 15 17 | syldan |  |-  ( ( G e. AbelOp /\ ( A e. X /\ B e. X /\ C e. X ) ) -> ( B G ( A D C ) ) = ( ( A D C ) G B ) ) | 
						
							| 19 | 5 10 18 | 3eqtrd |  |-  ( ( G e. AbelOp /\ ( A e. X /\ B e. X /\ C e. X ) ) -> ( ( A G B ) D C ) = ( ( A D C ) G B ) ) |