| Step | Hyp | Ref | Expression | 
						
							| 1 |  | idlval.1 |  | 
						
							| 2 |  | idlval.2 |  | 
						
							| 3 |  | idlval.3 |  | 
						
							| 4 |  | idlval.4 |  | 
						
							| 5 | 1 2 3 4 | idlval |  | 
						
							| 6 | 5 | eleq2d |  | 
						
							| 7 | 1 | fvexi |  | 
						
							| 8 | 7 | rnex |  | 
						
							| 9 | 3 8 | eqeltri |  | 
						
							| 10 | 9 | elpw2 |  | 
						
							| 11 | 10 | anbi1i |  | 
						
							| 12 |  | eleq2 |  | 
						
							| 13 |  | eleq2 |  | 
						
							| 14 | 13 | raleqbi1dv |  | 
						
							| 15 |  | eleq2 |  | 
						
							| 16 |  | eleq2 |  | 
						
							| 17 | 15 16 | anbi12d |  | 
						
							| 18 | 17 | ralbidv |  | 
						
							| 19 | 14 18 | anbi12d |  | 
						
							| 20 | 19 | raleqbi1dv |  | 
						
							| 21 | 12 20 | anbi12d |  | 
						
							| 22 | 21 | elrab |  | 
						
							| 23 |  | 3anass |  | 
						
							| 24 | 11 22 23 | 3bitr4i |  | 
						
							| 25 | 6 24 | bitrdi |  |