| Step | Hyp | Ref | Expression | 
						
							| 1 |  | pridl.1 |  | 
						
							| 2 |  | eqid |  | 
						
							| 3 |  | eqid |  | 
						
							| 4 | 2 1 3 | ispridl |  | 
						
							| 5 |  | df-3an |  | 
						
							| 6 | 4 5 | bitrdi |  | 
						
							| 7 | 6 | simplbda |  | 
						
							| 8 |  | raleq |  | 
						
							| 9 |  | sseq1 |  | 
						
							| 10 | 9 | orbi1d |  | 
						
							| 11 | 8 10 | imbi12d |  | 
						
							| 12 |  | raleq |  | 
						
							| 13 | 12 | ralbidv |  | 
						
							| 14 |  | sseq1 |  | 
						
							| 15 | 14 | orbi2d |  | 
						
							| 16 | 13 15 | imbi12d |  | 
						
							| 17 | 11 16 | rspc2v |  | 
						
							| 18 | 7 17 | syl5com |  | 
						
							| 19 | 18 | expd |  | 
						
							| 20 | 19 | 3imp2 |  |