| Step | Hyp | Ref | Expression | 
						
							| 1 |  | df-rab |  | 
						
							| 2 |  | r19.42v |  | 
						
							| 3 | 2 | bicomi |  | 
						
							| 4 | 3 | abbii |  | 
						
							| 5 |  | df-rex |  | 
						
							| 6 | 5 | abbii |  | 
						
							| 7 | 1 4 6 | 3eqtri |  | 
						
							| 8 |  | abid2 |  | 
						
							| 9 | 8 | ovexi |  | 
						
							| 10 |  | tru |  | 
						
							| 11 | 10 10 | pm3.2i |  | 
						
							| 12 |  | ovexd |  | 
						
							| 13 |  | eqtr3 |  | 
						
							| 14 | 13 | ex |  | 
						
							| 15 | 14 | eqcoms |  | 
						
							| 16 | 15 | adantl |  | 
						
							| 17 | 16 | com12 |  | 
						
							| 18 | 17 | ad2antlr |  | 
						
							| 19 | 18 | alrimiv |  | 
						
							| 20 | 19 | ex |  | 
						
							| 21 | 12 20 | spcimedv |  | 
						
							| 22 | 21 | imp |  | 
						
							| 23 | 11 22 | mp1i |  | 
						
							| 24 | 9 23 | zfrep4 |  | 
						
							| 25 | 7 24 | eqeltri |  |