| Step | Hyp | Ref | Expression | 
						
							| 1 |  | opprirred.1 |  | 
						
							| 2 |  | opprirred.2 |  | 
						
							| 3 |  | ralcom |  | 
						
							| 4 |  | eqid |  | 
						
							| 5 |  | eqid |  | 
						
							| 6 |  | eqid |  | 
						
							| 7 | 4 5 1 6 | opprmul |  | 
						
							| 8 | 7 | neeq1i |  | 
						
							| 9 | 8 | 2ralbii |  | 
						
							| 10 | 3 9 | bitr4i |  | 
						
							| 11 | 10 | anbi2i |  | 
						
							| 12 |  | eqid |  | 
						
							| 13 |  | eqid |  | 
						
							| 14 | 4 12 2 13 5 | isirred |  | 
						
							| 15 | 1 4 | opprbas |  | 
						
							| 16 | 12 1 | opprunit |  | 
						
							| 17 |  | eqid |  | 
						
							| 18 | 15 16 17 13 6 | isirred |  | 
						
							| 19 | 11 14 18 | 3bitr4i |  | 
						
							| 20 | 19 | eqriv |  |