| Step | Hyp | Ref | Expression | 
						
							| 1 |  | doch11.h |  | 
						
							| 2 |  | doch11.i |  | 
						
							| 3 |  | doch11.o |  | 
						
							| 4 |  | doch11.k |  | 
						
							| 5 |  | doch11.x |  | 
						
							| 6 |  | doch11.y |  | 
						
							| 7 |  | eqid |  | 
						
							| 8 |  | eqid |  | 
						
							| 9 | 1 7 2 8 | dihrnlss |  | 
						
							| 10 | 4 6 9 | syl2anc |  | 
						
							| 11 |  | eqid |  | 
						
							| 12 | 11 8 | lssss |  | 
						
							| 13 | 10 12 | syl |  | 
						
							| 14 | 1 2 7 11 3 | dochcl |  | 
						
							| 15 | 4 13 14 | syl2anc |  | 
						
							| 16 | 1 2 3 4 5 15 | dochord |  | 
						
							| 17 | 1 2 3 | dochoc |  | 
						
							| 18 | 4 6 17 | syl2anc |  | 
						
							| 19 | 18 | sseq1d |  | 
						
							| 20 | 16 19 | bitrd |  |