| Step | Hyp | Ref | Expression | 
						
							| 1 |  | dprdf1.1 |  | 
						
							| 2 |  | dprdf1.2 |  | 
						
							| 3 |  | dprdf1.3 |  | 
						
							| 4 |  | f1f |  | 
						
							| 5 |  | frn |  | 
						
							| 6 | 3 4 5 | 3syl |  | 
						
							| 7 | 1 2 6 | dprdres |  | 
						
							| 8 | 7 | simpld |  | 
						
							| 9 | 1 2 | dprdf2 |  | 
						
							| 10 | 9 6 | fssresd |  | 
						
							| 11 | 10 | fdmd |  | 
						
							| 12 |  | f1f1orn |  | 
						
							| 13 | 3 12 | syl |  | 
						
							| 14 | 8 11 13 | dprdf1o |  | 
						
							| 15 | 14 | simpld |  | 
						
							| 16 |  | ssid |  | 
						
							| 17 |  | cores |  | 
						
							| 18 | 16 17 | ax-mp |  | 
						
							| 19 | 15 18 | breqtrdi |  | 
						
							| 20 | 18 | oveq2i |  | 
						
							| 21 | 14 | simprd |  | 
						
							| 22 | 20 21 | eqtr3id |  | 
						
							| 23 | 7 | simprd |  | 
						
							| 24 | 22 23 | eqsstrd |  | 
						
							| 25 | 19 24 | jca |  |