| Step | Hyp | Ref | Expression | 
						
							| 1 |  | sltval2 |  | 
						
							| 2 |  | fvex |  | 
						
							| 3 |  | fvex |  | 
						
							| 4 | 2 3 | brtp |  | 
						
							| 5 |  | df-3or |  | 
						
							| 6 |  | ndmfv |  | 
						
							| 7 |  | 1oex |  | 
						
							| 8 | 7 | prid1 |  | 
						
							| 9 | 8 | nosgnn0i |  | 
						
							| 10 |  | neeq1 |  | 
						
							| 11 | 9 10 | mpbiri |  | 
						
							| 12 | 11 | neneqd |  | 
						
							| 13 | 12 | intnanrd |  | 
						
							| 14 | 12 | intnanrd |  | 
						
							| 15 |  | ioran |  | 
						
							| 16 | 13 14 15 | sylanbrc |  | 
						
							| 17 | 6 16 | syl |  | 
						
							| 18 | 17 | adantl |  | 
						
							| 19 |  | orel1 |  | 
						
							| 20 | 18 19 | syl |  | 
						
							| 21 | 5 20 | biimtrid |  | 
						
							| 22 |  | ndmfv |  | 
						
							| 23 |  | 2on |  | 
						
							| 24 | 23 | elexi |  | 
						
							| 25 | 24 | prid2 |  | 
						
							| 26 | 25 | nosgnn0i |  | 
						
							| 27 |  | neeq1 |  | 
						
							| 28 | 26 27 | mpbiri |  | 
						
							| 29 | 22 28 | syl |  | 
						
							| 30 | 29 | neneqd |  | 
						
							| 31 | 30 | con4i |  | 
						
							| 32 | 31 | adantl |  | 
						
							| 33 | 21 32 | syl6 |  | 
						
							| 34 | 33 | ex |  | 
						
							| 35 | 34 | com23 |  | 
						
							| 36 | 4 35 | biimtrid |  | 
						
							| 37 | 1 36 | sylbid |  | 
						
							| 38 | 37 | 3impia |  | 
						
							| 39 | 38 | orrd |  | 
						
							| 40 |  | elun |  | 
						
							| 41 | 39 40 | sylibr |  |