| Step | Hyp | Ref | Expression | 
						
							| 1 |  | rhmf1o.b |  |-  B = ( Base ` R ) | 
						
							| 2 |  | rhmf1o.c |  |-  C = ( Base ` S ) | 
						
							| 3 |  | isrim0 |  |-  ( F e. ( R RingIso S ) <-> ( F e. ( R RingHom S ) /\ `' F e. ( S RingHom R ) ) ) | 
						
							| 4 | 1 2 | rhmf1o |  |-  ( F e. ( R RingHom S ) -> ( F : B -1-1-onto-> C <-> `' F e. ( S RingHom R ) ) ) | 
						
							| 5 | 4 | bicomd |  |-  ( F e. ( R RingHom S ) -> ( `' F e. ( S RingHom R ) <-> F : B -1-1-onto-> C ) ) | 
						
							| 6 | 5 | pm5.32i |  |-  ( ( F e. ( R RingHom S ) /\ `' F e. ( S RingHom R ) ) <-> ( F e. ( R RingHom S ) /\ F : B -1-1-onto-> C ) ) | 
						
							| 7 | 3 6 | bitri |  |-  ( F e. ( R RingIso S ) <-> ( F e. ( R RingHom S ) /\ F : B -1-1-onto-> C ) ) |