| Step | Hyp | Ref | Expression | 
						
							| 1 |  | ax-1cn |  | 
						
							| 2 | 1 | a1i |  | 
						
							| 3 |  | id |  | 
						
							| 4 | 2 3 | subcld |  | 
						
							| 5 | 4 | adantr |  | 
						
							| 6 |  | subeq0 |  | 
						
							| 7 | 6 | biimpd |  | 
						
							| 8 | 7 | idiALT |  | 
						
							| 9 | 1 3 8 | sylancr |  | 
						
							| 10 | 9 | con3d |  | 
						
							| 11 |  | df-ne |  | 
						
							| 12 | 11 | biimpri |  | 
						
							| 13 | 10 12 | syl6 |  | 
						
							| 14 | 13 | imp |  | 
						
							| 15 | 5 14 | logcld |  | 
						
							| 16 | 15 | imcld |  | 
						
							| 17 | 16 | 3adant2 |  | 
						
							| 18 |  | pire |  | 
						
							| 19 |  | 2re |  | 
						
							| 20 |  | 2ne0 |  | 
						
							| 21 | 18 19 20 | redivcli |  | 
						
							| 22 | 21 | a1i |  | 
						
							| 23 | 18 | a1i |  | 
						
							| 24 |  | neghalfpirx |  | 
						
							| 25 | 21 | rexri |  | 
						
							| 26 | 3 | recld |  | 
						
							| 27 | 26 | recnd |  | 
						
							| 28 | 27 | subidd |  | 
						
							| 29 | 28 | adantr |  | 
						
							| 30 |  | 1re |  | 
						
							| 31 | 30 | a1i |  | 
						
							| 32 | 1 31 | ax-mp |  | 
						
							| 33 | 3 | releabsd |  | 
						
							| 34 | 33 | adantr |  | 
						
							| 35 |  | id |  | 
						
							| 36 | 35 | adantl |  | 
						
							| 37 | 34 36 | breqtrd |  | 
						
							| 38 |  | lesub1 |  | 
						
							| 39 | 38 | 3impcombi |  | 
						
							| 40 | 39 | idiALT |  | 
						
							| 41 | 32 26 37 40 | mp3an2ani |  | 
						
							| 42 | 29 41 | eqbrtrrd |  | 
						
							| 43 | 32 | a1i |  | 
						
							| 44 | 43 | rered |  | 
						
							| 45 | 44 | mptru |  | 
						
							| 46 |  | oveq1 |  | 
						
							| 47 | 46 | eqcomd |  | 
						
							| 48 | 45 47 | ax-mp |  | 
						
							| 49 |  | resub |  | 
						
							| 50 | 49 | eqcomd |  | 
						
							| 51 | 50 | idiALT |  | 
						
							| 52 | 1 3 51 | sylancr |  | 
						
							| 53 | 48 52 | eqtrid |  | 
						
							| 54 | 53 | adantr |  | 
						
							| 55 | 42 54 | breqtrd |  | 
						
							| 56 |  | argrege0 |  | 
						
							| 57 | 56 | 3coml |  | 
						
							| 58 | 57 | 3com13 |  | 
						
							| 59 | 4 55 14 58 | eel12131 |  | 
						
							| 60 |  | iccleub |  | 
						
							| 61 | 24 25 59 60 | mp3an12i |  | 
						
							| 62 |  | pipos |  | 
						
							| 63 | 18 62 | elrpii |  | 
						
							| 64 |  | rphalflt |  | 
						
							| 65 | 63 64 | ax-mp |  | 
						
							| 66 | 65 | a1i |  | 
						
							| 67 | 17 22 23 61 66 | lelttrd |  | 
						
							| 68 | 17 67 | ltned |  |