| Step | Hyp | Ref | Expression | 
						
							| 1 |  | oacomf1olem.1 |  | 
						
							| 2 |  | oaf1o |  | 
						
							| 3 | 2 | adantl |  | 
						
							| 4 |  | f1of1 |  | 
						
							| 5 | 3 4 | syl |  | 
						
							| 6 |  | onss |  | 
						
							| 7 | 6 | adantr |  | 
						
							| 8 |  | f1ssres |  | 
						
							| 9 | 5 7 8 | syl2anc |  | 
						
							| 10 | 7 | resmptd |  | 
						
							| 11 | 10 1 | eqtr4di |  | 
						
							| 12 |  | f1eq1 |  | 
						
							| 13 | 11 12 | syl |  | 
						
							| 14 | 9 13 | mpbid |  | 
						
							| 15 |  | f1f1orn |  | 
						
							| 16 | 14 15 | syl |  | 
						
							| 17 |  | f1f |  | 
						
							| 18 |  | frn |  | 
						
							| 19 | 14 17 18 | 3syl |  | 
						
							| 20 | 19 | difss2d |  | 
						
							| 21 |  | reldisj |  | 
						
							| 22 | 20 21 | syl |  | 
						
							| 23 | 19 22 | mpbird |  | 
						
							| 24 | 16 23 | jca |  |