| Step | Hyp | Ref | Expression | 
						
							| 1 |  | elfzle2 |  | 
						
							| 2 | 1 | adantl |  | 
						
							| 3 |  | elfzelz |  | 
						
							| 4 | 3 | adantl |  | 
						
							| 5 |  | nnz |  | 
						
							| 6 | 5 | adantr |  | 
						
							| 7 |  | zltlem1 |  | 
						
							| 8 | 4 6 7 | syl2anc |  | 
						
							| 9 | 2 8 | mpbird |  | 
						
							| 10 |  | elfznn |  | 
						
							| 11 | 10 | adantl |  | 
						
							| 12 | 11 | nnred |  | 
						
							| 13 |  | nnre |  | 
						
							| 14 | 13 | adantr |  | 
						
							| 15 | 12 14 | ltnled |  | 
						
							| 16 | 9 15 | mpbid |  | 
						
							| 17 |  | dvdsle |  | 
						
							| 18 | 6 11 17 | syl2anc |  | 
						
							| 19 | 16 18 | mtod |  |