| Step | Hyp | Ref | Expression | 
						
							| 1 |  | ipsubdir.1 |  | 
						
							| 2 |  | ipsubdir.3 |  | 
						
							| 3 |  | ipsubdir.7 |  | 
						
							| 4 |  | idd |  | 
						
							| 5 |  | phnv |  | 
						
							| 6 |  | neg1cn |  | 
						
							| 7 |  | eqid |  | 
						
							| 8 | 1 7 | nvscl |  | 
						
							| 9 | 6 8 | mp3an2 |  | 
						
							| 10 | 5 9 | sylan |  | 
						
							| 11 | 10 | ex |  | 
						
							| 12 |  | idd |  | 
						
							| 13 | 4 11 12 | 3anim123d |  | 
						
							| 14 | 13 | imp |  | 
						
							| 15 |  | eqid |  | 
						
							| 16 | 1 15 3 | dipdir |  | 
						
							| 17 | 14 16 | syldan |  | 
						
							| 18 | 1 15 7 2 | nvmval |  | 
						
							| 19 | 5 18 | syl3an1 |  | 
						
							| 20 | 19 | 3adant3r3 |  | 
						
							| 21 | 20 | oveq1d |  | 
						
							| 22 | 1 7 3 | dipass |  | 
						
							| 23 | 6 22 | mp3anr1 |  | 
						
							| 24 | 1 3 | dipcl |  | 
						
							| 25 | 24 | 3expb |  | 
						
							| 26 | 5 25 | sylan |  | 
						
							| 27 | 26 | mulm1d |  | 
						
							| 28 | 23 27 | eqtrd |  | 
						
							| 29 | 28 | 3adantr1 |  | 
						
							| 30 | 29 | oveq2d |  | 
						
							| 31 | 1 3 | dipcl |  | 
						
							| 32 | 31 | 3adant3r2 |  | 
						
							| 33 | 24 | 3adant3r1 |  | 
						
							| 34 | 32 33 | negsubd |  | 
						
							| 35 | 5 34 | sylan |  | 
						
							| 36 | 30 35 | eqtr2d |  | 
						
							| 37 | 17 21 36 | 3eqtr4d |  |