| Step | Hyp | Ref | Expression | 
						
							| 1 |  | signslema.1 |  | 
						
							| 2 |  | signslema.2 |  | 
						
							| 3 |  | signslema.3 |  | 
						
							| 4 |  | signslema.4 |  | 
						
							| 5 |  | signslema.5 |  | 
						
							| 6 |  | signslema.6 |  | 
						
							| 7 | 5 | simpld |  | 
						
							| 8 | 7 | adantr |  | 
						
							| 9 | 4 | nn0cnd |  | 
						
							| 10 | 2 | nn0cnd |  | 
						
							| 11 | 9 10 | subcld |  | 
						
							| 12 | 3 | nn0cnd |  | 
						
							| 13 | 1 | nn0cnd |  | 
						
							| 14 | 12 13 | subcld |  | 
						
							| 15 | 11 14 | subeq0ad |  | 
						
							| 16 | 15 | biimpa |  | 
						
							| 17 | 16 | breq2d |  | 
						
							| 18 | 2 | nn0red |  | 
						
							| 19 | 4 | nn0red |  | 
						
							| 20 | 18 19 | posdifd |  | 
						
							| 21 | 20 | adantr |  | 
						
							| 22 | 1 | nn0red |  | 
						
							| 23 | 3 | nn0red |  | 
						
							| 24 | 22 23 | posdifd |  | 
						
							| 25 | 24 | adantr |  | 
						
							| 26 | 17 21 25 | 3bitr4rd |  | 
						
							| 27 | 8 26 | mpbid |  | 
						
							| 28 |  | 0red |  | 
						
							| 29 | 23 22 | resubcld |  | 
						
							| 30 | 29 | adantr |  | 
						
							| 31 | 19 18 | resubcld |  | 
						
							| 32 | 31 | adantr |  | 
						
							| 33 | 7 | adantr |  | 
						
							| 34 | 24 | adantr |  | 
						
							| 35 | 33 34 | mpbid |  | 
						
							| 36 |  | 2pos |  | 
						
							| 37 |  | breq2 |  | 
						
							| 38 | 36 37 | mpbiri |  | 
						
							| 39 | 29 31 | posdifd |  | 
						
							| 40 | 39 | biimpar |  | 
						
							| 41 | 38 40 | sylan2 |  | 
						
							| 42 | 28 30 32 35 41 | lttrd |  | 
						
							| 43 | 20 | adantr |  | 
						
							| 44 | 42 43 | mpbird |  | 
						
							| 45 | 9 12 10 13 | sub4d |  | 
						
							| 46 | 45 6 | eqeltrrd |  | 
						
							| 47 |  | ovex |  | 
						
							| 48 | 47 | elpr |  | 
						
							| 49 | 46 48 | sylib |  | 
						
							| 50 | 27 44 49 | mpjaodan |  | 
						
							| 51 | 5 | simprd |  | 
						
							| 52 | 51 | adantr |  | 
						
							| 53 | 16 | breq2d |  | 
						
							| 54 | 52 53 | mtbird |  | 
						
							| 55 |  | 2z |  | 
						
							| 56 | 3 | nn0zd |  | 
						
							| 57 | 1 | nn0zd |  | 
						
							| 58 | 56 57 | zsubcld |  | 
						
							| 59 |  | dvdsaddr |  | 
						
							| 60 | 55 58 59 | sylancr |  | 
						
							| 61 | 51 60 | mtbid |  | 
						
							| 62 | 61 | adantr |  | 
						
							| 63 |  | 2cnd |  | 
						
							| 64 | 11 14 63 | subaddd |  | 
						
							| 65 | 64 | biimpa |  | 
						
							| 66 | 65 | breq2d |  | 
						
							| 67 | 62 66 | mtbid |  | 
						
							| 68 | 54 67 49 | mpjaodan |  | 
						
							| 69 | 50 68 | jca |  |