| Step | Hyp | Ref | Expression | 
						
							| 1 |  | isfldidl2.1 |  | 
						
							| 2 |  | isfldidl2.2 |  | 
						
							| 3 |  | isfldidl2.3 |  | 
						
							| 4 |  | isfldidl2.4 |  | 
						
							| 5 |  | eqid |  | 
						
							| 6 | 1 2 3 4 5 | isfldidl |  | 
						
							| 7 |  | crngorngo |  | 
						
							| 8 |  | eqcom |  | 
						
							| 9 | 1 2 3 4 5 | 0rngo |  | 
						
							| 10 | 8 9 | bitrid |  | 
						
							| 11 | 7 10 | syl |  | 
						
							| 12 | 11 | necon3bid |  | 
						
							| 13 | 12 | anbi1d |  | 
						
							| 14 | 13 | pm5.32i |  | 
						
							| 15 |  | 3anass |  | 
						
							| 16 |  | 3anass |  | 
						
							| 17 | 14 15 16 | 3bitr4i |  | 
						
							| 18 | 6 17 | bitri |  |