| Step | Hyp | Ref | Expression | 
						
							| 1 |  | sseq1 |  | 
						
							| 2 |  | fveq2 |  | 
						
							| 3 | 2 | ineq2d |  | 
						
							| 4 | 3 | eqeq1d |  | 
						
							| 5 | 1 4 | anbi12d |  | 
						
							| 6 |  | eqeq1 |  | 
						
							| 7 | 5 6 | imbi12d |  | 
						
							| 8 |  | sseq2 |  | 
						
							| 9 |  | ineq1 |  | 
						
							| 10 | 9 | eqeq1d |  | 
						
							| 11 | 8 10 | anbi12d |  | 
						
							| 12 |  | eqeq2 |  | 
						
							| 13 | 11 12 | imbi12d |  | 
						
							| 14 |  | h0elch |  | 
						
							| 15 | 14 | elimel |  | 
						
							| 16 |  | h0elsh |  | 
						
							| 17 | 16 | elimel |  | 
						
							| 18 | 15 17 | pjomli |  | 
						
							| 19 | 7 13 18 | dedth2h |  | 
						
							| 20 | 19 | imp |  |