| Step | Hyp | Ref | Expression | 
						
							| 1 |  | ablcom.1 |  | 
						
							| 2 |  | simprll |  | 
						
							| 3 |  | simprlr |  | 
						
							| 4 |  | simprrl |  | 
						
							| 5 | 2 3 4 | 3jca |  | 
						
							| 6 | 1 | ablo32 |  | 
						
							| 7 | 5 6 | syldan |  | 
						
							| 8 | 7 | oveq1d |  | 
						
							| 9 |  | ablogrpo |  | 
						
							| 10 | 1 | grpocl |  | 
						
							| 11 | 10 | 3expb |  | 
						
							| 12 | 11 | adantrr |  | 
						
							| 13 |  | simprrl |  | 
						
							| 14 |  | simprrr |  | 
						
							| 15 | 12 13 14 | 3jca |  | 
						
							| 16 | 1 | grpoass |  | 
						
							| 17 | 15 16 | syldan |  | 
						
							| 18 | 9 17 | sylan |  | 
						
							| 19 | 1 | grpocl |  | 
						
							| 20 | 19 | 3expb |  | 
						
							| 21 | 20 | adantrlr |  | 
						
							| 22 | 21 | adantrrr |  | 
						
							| 23 |  | simprlr |  | 
						
							| 24 | 22 23 14 | 3jca |  | 
						
							| 25 | 1 | grpoass |  | 
						
							| 26 | 24 25 | syldan |  | 
						
							| 27 | 9 26 | sylan |  | 
						
							| 28 | 8 18 27 | 3eqtr3d |  | 
						
							| 29 | 28 | 3impb |  |