| Step | Hyp | Ref | Expression | 
						
							| 1 |  | strlem3.1 |  | 
						
							| 2 |  | strlem3.2 |  | 
						
							| 3 |  | strlem3.3 |  | 
						
							| 4 |  | strlem3.4 |  | 
						
							| 5 | 1 | strlem2 |  | 
						
							| 6 | 4 5 | ax-mp |  | 
						
							| 7 |  | eldif |  | 
						
							| 8 | 3 | cheli |  | 
						
							| 9 |  | pjnel |  | 
						
							| 10 | 4 9 | mpan |  | 
						
							| 11 | 10 | biimpa |  | 
						
							| 12 | 8 11 | sylan |  | 
						
							| 13 | 7 12 | sylbi |  | 
						
							| 14 |  | breq2 |  | 
						
							| 15 | 13 14 | imbitrid |  | 
						
							| 16 | 15 | impcom |  | 
						
							| 17 |  | eldifi |  | 
						
							| 18 | 4 | pjhcli |  | 
						
							| 19 |  | normcl |  | 
						
							| 20 | 18 19 | syl |  | 
						
							| 21 |  | normge0 |  | 
						
							| 22 | 18 21 | syl |  | 
						
							| 23 |  | 1re |  | 
						
							| 24 |  | 0le1 |  | 
						
							| 25 |  | lt2sq |  | 
						
							| 26 | 23 24 25 | mpanr12 |  | 
						
							| 27 | 20 22 26 | syl2anc |  | 
						
							| 28 | 17 8 27 | 3syl |  | 
						
							| 29 | 28 | adantr |  | 
						
							| 30 | 16 29 | mpbid |  | 
						
							| 31 | 6 30 | eqbrtrid |  | 
						
							| 32 |  | sq1 |  | 
						
							| 33 | 31 32 | breqtrdi |  | 
						
							| 34 | 2 33 | sylbi |  |