| Step | Hyp | Ref | Expression | 
						
							| 1 |  | prmidlval.1 |  | 
						
							| 2 |  | prmidlval.2 |  | 
						
							| 3 |  | raleq |  | 
						
							| 4 | 3 | ralbidv |  | 
						
							| 5 |  | sseq1 |  | 
						
							| 6 | 5 | orbi2d |  | 
						
							| 7 | 4 6 | imbi12d |  | 
						
							| 8 |  | raleq |  | 
						
							| 9 |  | sseq1 |  | 
						
							| 10 | 9 | orbi1d |  | 
						
							| 11 | 8 10 | imbi12d |  | 
						
							| 12 | 11 | ralbidv |  | 
						
							| 13 | 1 2 | isprmidl |  | 
						
							| 14 | 13 | biimpa |  | 
						
							| 15 | 14 | simp3d |  | 
						
							| 16 | 15 | adantr |  | 
						
							| 17 |  | simprl |  | 
						
							| 18 | 12 16 17 | rspcdva |  | 
						
							| 19 |  | simprr |  | 
						
							| 20 | 7 18 19 | rspcdva |  | 
						
							| 21 | 20 | imp |  |