| Step | Hyp | Ref | Expression | 
						
							| 1 |  | xrltletr |  | 
						
							| 2 |  | id |  | 
						
							| 3 | 2 | impcom |  | 
						
							| 4 |  | xrltnle |  | 
						
							| 5 | 4 | 3adant2 |  | 
						
							| 6 | 5 | biimpd |  | 
						
							| 7 | 6 | imp |  | 
						
							| 8 | 7 | olcd |  | 
						
							| 9 | 8 | expcom |  | 
						
							| 10 | 3 9 | syl |  | 
						
							| 11 | 10 | ex |  | 
						
							| 12 | 11 | com23 |  | 
						
							| 13 | 12 | impd |  | 
						
							| 14 |  | id |  | 
						
							| 15 | 14 | orcd |  | 
						
							| 16 | 15 | a1d |  | 
						
							| 17 | 13 16 | pm2.61i |  | 
						
							| 18 |  | df-3an |  | 
						
							| 19 | 18 | notbii |  | 
						
							| 20 |  | ianor |  | 
						
							| 21 | 19 20 | bitri |  | 
						
							| 22 | 17 21 | sylibr |  | 
						
							| 23 | 22 | ex |  | 
						
							| 24 | 1 23 | mpd |  |