| Step | Hyp | Ref | Expression | 
						
							| 1 |  | edgval |  | 
						
							| 2 | 1 | a1i |  | 
						
							| 3 | 2 | eleq2d |  | 
						
							| 4 |  | eqid |  | 
						
							| 5 |  | eqid |  | 
						
							| 6 | 4 5 | upgrf |  | 
						
							| 7 | 6 | frnd |  | 
						
							| 8 | 7 | sseld |  | 
						
							| 9 |  | fveq2 |  | 
						
							| 10 | 9 | breq1d |  | 
						
							| 11 | 10 | elrab |  | 
						
							| 12 |  | eldifsn |  | 
						
							| 13 | 12 | biimpi |  | 
						
							| 14 | 13 | anim1i |  | 
						
							| 15 |  | df-3an |  | 
						
							| 16 | 14 15 | sylibr |  | 
						
							| 17 | 16 | a1i |  | 
						
							| 18 | 11 17 | biimtrid |  | 
						
							| 19 | 8 18 | syld |  | 
						
							| 20 | 3 19 | sylbid |  | 
						
							| 21 | 20 | imp |  |