| Step | Hyp | Ref | Expression | 
						
							| 1 |  | isdrngdOLD.b |  | 
						
							| 2 |  | isdrngdOLD.t |  | 
						
							| 3 |  | isdrngdOLD.z |  | 
						
							| 4 |  | isdrngdOLD.u |  | 
						
							| 5 |  | isdrngdOLD.r |  | 
						
							| 6 |  | isdrngdOLD.n |  | 
						
							| 7 |  | isdrngdOLD.o |  | 
						
							| 8 |  | isdrngdOLD.i |  | 
						
							| 9 |  | isdrngdOLD.j |  | 
						
							| 10 |  | isdrngrdOLD.k |  | 
						
							| 11 |  | eqid |  | 
						
							| 12 |  | eqid |  | 
						
							| 13 | 11 12 | opprbas |  | 
						
							| 14 | 1 13 | eqtrdi |  | 
						
							| 15 |  | eqidd |  | 
						
							| 16 |  | eqid |  | 
						
							| 17 | 11 16 | oppr0 |  | 
						
							| 18 | 3 17 | eqtrdi |  | 
						
							| 19 |  | eqid |  | 
						
							| 20 | 11 19 | oppr1 |  | 
						
							| 21 | 4 20 | eqtrdi |  | 
						
							| 22 | 11 | opprring |  | 
						
							| 23 | 5 22 | syl |  | 
						
							| 24 |  | eleq1w |  | 
						
							| 25 |  | neeq1 |  | 
						
							| 26 | 24 25 | anbi12d |  | 
						
							| 27 | 26 | 3anbi2d |  | 
						
							| 28 |  | oveq1 |  | 
						
							| 29 | 28 | neeq1d |  | 
						
							| 30 | 27 29 | imbi12d |  | 
						
							| 31 |  | eleq1w |  | 
						
							| 32 |  | neeq1 |  | 
						
							| 33 | 31 32 | anbi12d |  | 
						
							| 34 | 33 | 3anbi3d |  | 
						
							| 35 |  | oveq2 |  | 
						
							| 36 | 35 | neeq1d |  | 
						
							| 37 | 34 36 | imbi12d |  | 
						
							| 38 | 2 | 3ad2ant1 |  | 
						
							| 39 | 38 | oveqd |  | 
						
							| 40 |  | eqid |  | 
						
							| 41 |  | eqid |  | 
						
							| 42 | 12 40 11 41 | opprmul |  | 
						
							| 43 | 39 42 | eqtr4di |  | 
						
							| 44 | 43 6 | eqnetrrd |  | 
						
							| 45 | 44 | 3com23 |  | 
						
							| 46 | 37 45 | chvarvv |  | 
						
							| 47 | 30 46 | chvarvv |  | 
						
							| 48 | 12 40 11 41 | opprmul |  | 
						
							| 49 | 2 | adantr |  | 
						
							| 50 | 49 | oveqd |  | 
						
							| 51 | 50 10 | eqtr3d |  | 
						
							| 52 | 48 51 | eqtrid |  | 
						
							| 53 | 14 15 18 21 23 47 7 8 9 52 | isdrngdOLD |  | 
						
							| 54 | 11 | opprdrng |  | 
						
							| 55 | 53 54 | sylibr |  |