| Step | Hyp | Ref | Expression | 
						
							| 1 |  | breq1 |  | 
						
							| 2 |  | eqeq1 |  | 
						
							| 3 |  | breq2 |  | 
						
							| 4 | 1 2 3 | 3orbi123d |  | 
						
							| 5 | 4 | imbi2d |  | 
						
							| 6 |  | breq2 |  | 
						
							| 7 |  | eqeq2 |  | 
						
							| 8 |  | breq1 |  | 
						
							| 9 | 6 7 8 | 3orbi123d |  | 
						
							| 10 | 9 | imbi2d |  | 
						
							| 11 |  | df-so |  | 
						
							| 12 |  | breq1 |  | 
						
							| 13 |  | equequ1 |  | 
						
							| 14 |  | breq2 |  | 
						
							| 15 | 12 13 14 | 3orbi123d |  | 
						
							| 16 | 15 | ralbidv |  | 
						
							| 17 | 16 | rspw |  | 
						
							| 18 |  | breq2 |  | 
						
							| 19 |  | equequ2 |  | 
						
							| 20 |  | breq1 |  | 
						
							| 21 | 18 19 20 | 3orbi123d |  | 
						
							| 22 | 21 | rspw |  | 
						
							| 23 | 17 22 | syl6 |  | 
						
							| 24 | 23 | impd |  | 
						
							| 25 | 11 24 | simplbiim |  | 
						
							| 26 | 25 | com12 |  | 
						
							| 27 | 5 10 26 | vtocl2ga |  | 
						
							| 28 | 27 | impcom |  |