| Step | Hyp | Ref | Expression | 
						
							| 1 |  | upwordsing.1 |  | 
						
							| 2 |  | s1cl |  | 
						
							| 3 |  | elab6g |  | 
						
							| 4 | 1 2 3 | mp2b |  | 
						
							| 5 |  | eleq1a |  | 
						
							| 6 | 1 2 5 | mp2b |  | 
						
							| 7 |  | fveq2 |  | 
						
							| 8 | 7 | oveq1d |  | 
						
							| 9 |  | s1len |  | 
						
							| 10 | 9 | oveq1i |  | 
						
							| 11 |  | 1m1e0 |  | 
						
							| 12 | 10 11 | eqtri |  | 
						
							| 13 | 8 12 | eqtrdi |  | 
						
							| 14 | 13 | oveq2d |  | 
						
							| 15 |  | fzo0 |  | 
						
							| 16 | 14 15 | eqtrdi |  | 
						
							| 17 |  | rzal |  | 
						
							| 18 | 16 17 | syl |  | 
						
							| 19 | 6 18 | jca |  | 
						
							| 20 | 4 19 | mpgbir |  | 
						
							| 21 |  | df-upword |  | 
						
							| 22 | 20 21 | eleqtrri |  |