| Step | Hyp | Ref | Expression | 
						
							| 1 |  | dmdbr4 |  | 
						
							| 2 |  | chub1 |  | 
						
							| 3 | 2 | ancoms |  | 
						
							| 4 |  | ssin |  | 
						
							| 5 |  | sstr2 |  | 
						
							| 6 | 4 5 | sylbi |  | 
						
							| 7 | 3 6 | sylan |  | 
						
							| 8 | 7 | ex |  | 
						
							| 9 | 8 | com23 |  | 
						
							| 10 | 9 | ralimdva |  | 
						
							| 11 | 10 | adantl |  | 
						
							| 12 | 1 11 | sylbid |  | 
						
							| 13 |  | sseq1 |  | 
						
							| 14 |  | id |  | 
						
							| 15 |  | oveq1 |  | 
						
							| 16 | 15 | ineq1d |  | 
						
							| 17 | 16 | oveq1d |  | 
						
							| 18 | 14 17 | sseq12d |  | 
						
							| 19 | 13 18 | imbi12d |  | 
						
							| 20 | 19 | rspccv |  | 
						
							| 21 |  | chjcl |  | 
						
							| 22 | 21 | ancoms |  | 
						
							| 23 | 22 | adantll |  | 
						
							| 24 |  | chjcl |  | 
						
							| 25 | 24 | adantr |  | 
						
							| 26 |  | chincl |  | 
						
							| 27 | 23 25 26 | syl2anc |  | 
						
							| 28 |  | inss2 |  | 
						
							| 29 |  | pm2.27 |  | 
						
							| 30 | 28 29 | mpii |  | 
						
							| 31 | 27 30 | syl |  | 
						
							| 32 |  | chub2 |  | 
						
							| 33 | 32 | adantll |  | 
						
							| 34 |  | chub2 |  | 
						
							| 35 | 34 | ancoms |  | 
						
							| 36 | 35 | adantr |  | 
						
							| 37 | 33 36 | ssind |  | 
						
							| 38 |  | simplr |  | 
						
							| 39 |  | chlejb2 |  | 
						
							| 40 | 38 27 39 | syl2anc |  | 
						
							| 41 | 37 40 | mpbid |  | 
						
							| 42 | 41 | ineq1d |  | 
						
							| 43 |  | inass |  | 
						
							| 44 |  | incom |  | 
						
							| 45 |  | chabs2 |  | 
						
							| 46 | 44 45 | eqtrid |  | 
						
							| 47 | 46 | ineq2d |  | 
						
							| 48 | 43 47 | eqtrid |  | 
						
							| 49 | 48 | adantr |  | 
						
							| 50 | 42 49 | eqtrd |  | 
						
							| 51 | 50 | oveq1d |  | 
						
							| 52 | 51 | sseq2d |  | 
						
							| 53 | 31 52 | sylibd |  | 
						
							| 54 | 53 | ex |  | 
						
							| 55 | 54 | com23 |  | 
						
							| 56 | 20 55 | syl5 |  | 
						
							| 57 | 56 | ralrimdv |  | 
						
							| 58 |  | dmdbr4 |  | 
						
							| 59 | 57 58 | sylibrd |  | 
						
							| 60 | 12 59 | impbid |  |