| Step | Hyp | Ref | Expression | 
						
							| 1 |  | strlem1.1 |  | 
						
							| 2 |  | strlem1.2 |  | 
						
							| 3 |  | neq0 |  | 
						
							| 4 |  | ssdif0 |  | 
						
							| 5 | 3 4 | xchnxbir |  | 
						
							| 6 |  | eldifi |  | 
						
							| 7 | 1 | cheli |  | 
						
							| 8 |  | normcl |  | 
						
							| 9 | 6 7 8 | 3syl |  | 
						
							| 10 |  | ch0 |  | 
						
							| 11 | 2 10 | ax-mp |  | 
						
							| 12 |  | eldifn |  | 
						
							| 13 | 11 12 | mt2 |  | 
						
							| 14 |  | eleq1 |  | 
						
							| 15 | 13 14 | mtbiri |  | 
						
							| 16 | 15 | con2i |  | 
						
							| 17 |  | norm-i |  | 
						
							| 18 | 6 7 17 | 3syl |  | 
						
							| 19 | 16 18 | mtbird |  | 
						
							| 20 | 19 | neqned |  | 
						
							| 21 | 9 20 | rereccld |  | 
						
							| 22 | 21 | recnd |  | 
						
							| 23 | 1 | chshii |  | 
						
							| 24 |  | shmulcl |  | 
						
							| 25 | 23 24 | mp3an1 |  | 
						
							| 26 | 25 | ex |  | 
						
							| 27 | 22 26 | syl |  | 
						
							| 28 | 9 | recnd |  | 
						
							| 29 | 2 | chshii |  | 
						
							| 30 |  | shmulcl |  | 
						
							| 31 | 29 30 | mp3an1 |  | 
						
							| 32 | 31 | ex |  | 
						
							| 33 | 28 32 | syl |  | 
						
							| 34 | 28 20 | recidd |  | 
						
							| 35 | 34 | oveq1d |  | 
						
							| 36 | 6 7 | syl |  | 
						
							| 37 |  | ax-hvmulass |  | 
						
							| 38 | 28 22 36 37 | syl3anc |  | 
						
							| 39 |  | ax-hvmulid |  | 
						
							| 40 | 6 7 39 | 3syl |  | 
						
							| 41 | 35 38 40 | 3eqtr3d |  | 
						
							| 42 | 41 | eleq1d |  | 
						
							| 43 | 33 42 | sylibd |  | 
						
							| 44 | 43 | con3d |  | 
						
							| 45 | 27 44 | anim12d |  | 
						
							| 46 |  | eldif |  | 
						
							| 47 |  | eldif |  | 
						
							| 48 | 45 46 47 | 3imtr4g |  | 
						
							| 49 | 48 | pm2.43i |  | 
						
							| 50 |  | norm-iii |  | 
						
							| 51 | 22 36 50 | syl2anc |  | 
						
							| 52 | 15 | necon2ai |  | 
						
							| 53 |  | normgt0 |  | 
						
							| 54 | 6 7 53 | 3syl |  | 
						
							| 55 | 52 54 | mpbid |  | 
						
							| 56 |  | 1re |  | 
						
							| 57 |  | 0le1 |  | 
						
							| 58 |  | divge0 |  | 
						
							| 59 | 56 57 58 | mpanl12 |  | 
						
							| 60 | 9 55 59 | syl2anc |  | 
						
							| 61 | 21 60 | absidd |  | 
						
							| 62 | 61 | oveq1d |  | 
						
							| 63 | 28 20 | recid2d |  | 
						
							| 64 | 51 62 63 | 3eqtrd |  | 
						
							| 65 |  | fveqeq2 |  | 
						
							| 66 | 65 | rspcev |  | 
						
							| 67 | 49 64 66 | syl2anc |  | 
						
							| 68 | 67 | exlimiv |  | 
						
							| 69 | 5 68 | sylbi |  |