| Step | Hyp | Ref | Expression | 
						
							| 1 |  | dib11.b |  | 
						
							| 2 |  | dib11.l |  | 
						
							| 3 |  | dib11.h |  | 
						
							| 4 |  | dib11.i |  | 
						
							| 5 |  | eqid |  | 
						
							| 6 |  | eqid |  | 
						
							| 7 |  | eqid |  | 
						
							| 8 | 1 2 3 5 6 7 4 | dibval2 |  | 
						
							| 9 | 8 | 3adant3 |  | 
						
							| 10 | 1 2 3 5 6 7 4 | dibval2 |  | 
						
							| 11 | 10 | 3adant2 |  | 
						
							| 12 | 9 11 | sseq12d |  | 
						
							| 13 | 1 2 3 4 | dibn0 |  | 
						
							| 14 | 13 | 3adant3 |  | 
						
							| 15 | 9 14 | eqnetrrd |  | 
						
							| 16 |  | ssxpb |  | 
						
							| 17 | 15 16 | syl |  | 
						
							| 18 |  | ssid |  | 
						
							| 19 | 18 | biantru |  | 
						
							| 20 | 1 2 3 7 | diaord |  | 
						
							| 21 | 19 20 | bitr3id |  | 
						
							| 22 | 12 17 21 | 3bitrd |  |