| Step | Hyp | Ref | Expression | 
						
							| 1 |  | erclwwlkn.w |  | 
						
							| 2 |  | erclwwlkn.r |  | 
						
							| 3 |  | elqsecl |  | 
						
							| 4 | 1 2 | erclwwlknsym |  | 
						
							| 5 | 1 2 | erclwwlknsym |  | 
						
							| 6 | 4 5 | impbii |  | 
						
							| 7 | 6 | a1i |  | 
						
							| 8 | 7 | abbidv |  | 
						
							| 9 | 1 2 | erclwwlkneq |  | 
						
							| 10 | 9 | el2v |  | 
						
							| 11 | 10 | a1i |  | 
						
							| 12 | 11 | abbidv |  | 
						
							| 13 |  | 3anan12 |  | 
						
							| 14 |  | ibar |  | 
						
							| 15 | 14 | bicomd |  | 
						
							| 16 | 15 | adantl |  | 
						
							| 17 | 13 16 | bitrid |  | 
						
							| 18 | 17 | abbidv |  | 
						
							| 19 |  | df-rab |  | 
						
							| 20 | 18 19 | eqtr4di |  | 
						
							| 21 | 8 12 20 | 3eqtrd |  | 
						
							| 22 | 21 | eqeq2d |  | 
						
							| 23 | 22 | rexbidva |  | 
						
							| 24 | 3 23 | bitrd |  |