| Step | Hyp | Ref | Expression | 
						
							| 1 |  | abldiv.1 |  |-  X = ran G | 
						
							| 2 |  | abldiv.3 |  |-  D = ( /g ` G ) | 
						
							| 3 |  | ablogrpo |  |-  ( G e. AbelOp -> G e. GrpOp ) | 
						
							| 4 |  | simpl |  |-  ( ( G e. GrpOp /\ ( A e. X /\ B e. X /\ C e. X ) ) -> G e. GrpOp ) | 
						
							| 5 | 1 2 | grpodivcl |  |-  ( ( G e. GrpOp /\ A e. X /\ B e. X ) -> ( A D B ) e. X ) | 
						
							| 6 | 5 | 3adant3r3 |  |-  ( ( G e. GrpOp /\ ( A e. X /\ B e. X /\ C e. X ) ) -> ( A D B ) e. X ) | 
						
							| 7 |  | simpr3 |  |-  ( ( G e. GrpOp /\ ( A e. X /\ B e. X /\ C e. X ) ) -> C e. X ) | 
						
							| 8 |  | eqid |  |-  ( inv ` G ) = ( inv ` G ) | 
						
							| 9 | 1 8 2 | grpodivval |  |-  ( ( G e. GrpOp /\ ( A D B ) e. X /\ C e. X ) -> ( ( A D B ) D C ) = ( ( A D B ) G ( ( inv ` G ) ` C ) ) ) | 
						
							| 10 | 4 6 7 9 | syl3anc |  |-  ( ( G e. GrpOp /\ ( A e. X /\ B e. X /\ C e. X ) ) -> ( ( A D B ) D C ) = ( ( A D B ) G ( ( inv ` G ) ` C ) ) ) | 
						
							| 11 | 3 10 | sylan |  |-  ( ( G e. AbelOp /\ ( A e. X /\ B e. X /\ C e. X ) ) -> ( ( A D B ) D C ) = ( ( A D B ) G ( ( inv ` G ) ` C ) ) ) | 
						
							| 12 |  | simpr1 |  |-  ( ( G e. AbelOp /\ ( A e. X /\ B e. X /\ C e. X ) ) -> A e. X ) | 
						
							| 13 |  | simpr2 |  |-  ( ( G e. AbelOp /\ ( A e. X /\ B e. X /\ C e. X ) ) -> B e. X ) | 
						
							| 14 |  | simp3 |  |-  ( ( A e. X /\ B e. X /\ C e. X ) -> C e. X ) | 
						
							| 15 | 1 8 | grpoinvcl |  |-  ( ( G e. GrpOp /\ C e. X ) -> ( ( inv ` G ) ` C ) e. X ) | 
						
							| 16 | 3 14 15 | syl2an |  |-  ( ( G e. AbelOp /\ ( A e. X /\ B e. X /\ C e. X ) ) -> ( ( inv ` G ) ` C ) e. X ) | 
						
							| 17 | 12 13 16 | 3jca |  |-  ( ( G e. AbelOp /\ ( A e. X /\ B e. X /\ C e. X ) ) -> ( A e. X /\ B e. X /\ ( ( inv ` G ) ` C ) e. X ) ) | 
						
							| 18 | 1 2 | ablodivdiv |  |-  ( ( G e. AbelOp /\ ( A e. X /\ B e. X /\ ( ( inv ` G ) ` C ) e. X ) ) -> ( A D ( B D ( ( inv ` G ) ` C ) ) ) = ( ( A D B ) G ( ( inv ` G ) ` C ) ) ) | 
						
							| 19 | 17 18 | syldan |  |-  ( ( G e. AbelOp /\ ( A e. X /\ B e. X /\ C e. X ) ) -> ( A D ( B D ( ( inv ` G ) ` C ) ) ) = ( ( A D B ) G ( ( inv ` G ) ` C ) ) ) | 
						
							| 20 | 1 8 2 | grpodivinv |  |-  ( ( G e. GrpOp /\ B e. X /\ C e. X ) -> ( B D ( ( inv ` G ) ` C ) ) = ( B G C ) ) | 
						
							| 21 | 3 20 | syl3an1 |  |-  ( ( G e. AbelOp /\ B e. X /\ C e. X ) -> ( B D ( ( inv ` G ) ` C ) ) = ( B G C ) ) | 
						
							| 22 | 21 | 3adant3r1 |  |-  ( ( G e. AbelOp /\ ( A e. X /\ B e. X /\ C e. X ) ) -> ( B D ( ( inv ` G ) ` C ) ) = ( B G C ) ) | 
						
							| 23 | 22 | oveq2d |  |-  ( ( G e. AbelOp /\ ( A e. X /\ B e. X /\ C e. X ) ) -> ( A D ( B D ( ( inv ` G ) ` C ) ) ) = ( A D ( B G C ) ) ) | 
						
							| 24 | 11 19 23 | 3eqtr2d |  |-  ( ( G e. AbelOp /\ ( A e. X /\ B e. X /\ C e. X ) ) -> ( ( A D B ) D C ) = ( A D ( B G C ) ) ) |