| Step | Hyp | Ref | Expression | 
						
							| 1 |  | axacnd |  | 
						
							| 2 |  | df-an |  | 
						
							| 3 | 2 | albii |  | 
						
							| 4 |  | anass |  | 
						
							| 5 |  | annim |  | 
						
							| 6 |  | pm4.63 |  | 
						
							| 7 | 6 | anbi2i |  | 
						
							| 8 | 5 7 | bitr3i |  | 
						
							| 9 | 8 | anbi2i |  | 
						
							| 10 |  | annim |  | 
						
							| 11 | 4 9 10 | 3bitr2i |  | 
						
							| 12 | 11 | exbii |  | 
						
							| 13 |  | exnal |  | 
						
							| 14 | 12 13 | bitri |  | 
						
							| 15 | 14 | bibi1i |  | 
						
							| 16 |  | dfbi1 |  | 
						
							| 17 | 15 16 | bitri |  | 
						
							| 18 | 17 | albii |  | 
						
							| 19 | 18 | exbii |  | 
						
							| 20 |  | df-ex |  | 
						
							| 21 | 19 20 | bitri |  | 
						
							| 22 | 3 21 | imbi12i |  | 
						
							| 23 | 22 | 2albii |  | 
						
							| 24 | 23 | exbii |  | 
						
							| 25 |  | df-ex |  | 
						
							| 26 | 24 25 | bitri |  | 
						
							| 27 | 1 26 | mpbi |  |