| Step | Hyp | Ref | Expression | 
						
							| 1 |  | icoshftf1o.1 |  | 
						
							| 2 |  | icoshft |  | 
						
							| 3 | 2 | ralrimiv |  | 
						
							| 4 |  | readdcl |  | 
						
							| 5 | 4 | 3adant2 |  | 
						
							| 6 |  | readdcl |  | 
						
							| 7 | 6 | 3adant1 |  | 
						
							| 8 |  | renegcl |  | 
						
							| 9 | 8 | 3ad2ant3 |  | 
						
							| 10 |  | icoshft |  | 
						
							| 11 | 5 7 9 10 | syl3anc |  | 
						
							| 12 | 11 | imp |  | 
						
							| 13 | 7 | rexrd |  | 
						
							| 14 |  | icossre |  | 
						
							| 15 | 5 13 14 | syl2anc |  | 
						
							| 16 | 15 | sselda |  | 
						
							| 17 | 16 | recnd |  | 
						
							| 18 |  | simpl3 |  | 
						
							| 19 | 18 | recnd |  | 
						
							| 20 | 17 19 | negsubd |  | 
						
							| 21 | 5 | recnd |  | 
						
							| 22 |  | simp3 |  | 
						
							| 23 | 22 | recnd |  | 
						
							| 24 | 21 23 | negsubd |  | 
						
							| 25 |  | simp1 |  | 
						
							| 26 | 25 | recnd |  | 
						
							| 27 | 26 23 | pncand |  | 
						
							| 28 | 24 27 | eqtrd |  | 
						
							| 29 | 7 | recnd |  | 
						
							| 30 | 29 23 | negsubd |  | 
						
							| 31 |  | simp2 |  | 
						
							| 32 | 31 | recnd |  | 
						
							| 33 | 32 23 | pncand |  | 
						
							| 34 | 30 33 | eqtrd |  | 
						
							| 35 | 28 34 | oveq12d |  | 
						
							| 36 | 35 | adantr |  | 
						
							| 37 | 12 20 36 | 3eltr3d |  | 
						
							| 38 |  | reueq |  | 
						
							| 39 | 37 38 | sylib |  | 
						
							| 40 | 16 | adantr |  | 
						
							| 41 | 40 | recnd |  | 
						
							| 42 |  | simpll3 |  | 
						
							| 43 | 42 | recnd |  | 
						
							| 44 |  | simpl1 |  | 
						
							| 45 |  | simpl2 |  | 
						
							| 46 | 45 | rexrd |  | 
						
							| 47 |  | icossre |  | 
						
							| 48 | 44 46 47 | syl2anc |  | 
						
							| 49 | 48 | sselda |  | 
						
							| 50 | 49 | recnd |  | 
						
							| 51 | 41 43 50 | subadd2d |  | 
						
							| 52 |  | eqcom |  | 
						
							| 53 |  | eqcom |  | 
						
							| 54 | 51 52 53 | 3bitr4g |  | 
						
							| 55 | 54 | reubidva |  | 
						
							| 56 | 39 55 | mpbid |  | 
						
							| 57 | 56 | ralrimiva |  | 
						
							| 58 | 1 | f1ompt |  | 
						
							| 59 | 3 57 58 | sylanbrc |  |