| Step | Hyp | Ref | Expression | 
						
							| 1 |  | dstrvprob.1 |  | 
						
							| 2 |  | dstrvprob.2 |  | 
						
							| 3 |  | orvcelel.1 |  | 
						
							| 4 | 1 2 3 | orrvcval4 |  | 
						
							| 5 |  | epelg |  | 
						
							| 6 | 3 5 | syl |  | 
						
							| 7 | 6 | rabbidv |  | 
						
							| 8 |  | dfin5 |  | 
						
							| 9 | 8 | a1i |  | 
						
							| 10 |  | elssuni |  | 
						
							| 11 |  | unibrsiga |  | 
						
							| 12 | 10 11 | sseqtrdi |  | 
						
							| 13 | 3 12 | syl |  | 
						
							| 14 |  | sseqin2 |  | 
						
							| 15 | 13 14 | sylib |  | 
						
							| 16 | 7 9 15 | 3eqtr2d |  | 
						
							| 17 | 16 | imaeq2d |  | 
						
							| 18 | 4 17 | eqtrd |  |