| Step | Hyp | Ref | Expression | 
						
							| 1 |  | htpyid.1 |  | 
						
							| 2 |  | htpyid.2 |  | 
						
							| 3 |  | htpyid.4 |  | 
						
							| 4 |  | iitopon |  | 
						
							| 5 | 4 | a1i |  | 
						
							| 6 | 2 5 | cnmpt1st |  | 
						
							| 7 | 2 5 6 3 | cnmpt21f |  | 
						
							| 8 | 1 7 | eqeltrid |  | 
						
							| 9 |  | simpr |  | 
						
							| 10 |  | 0elunit |  | 
						
							| 11 |  | fveq2 |  | 
						
							| 12 |  | eqidd |  | 
						
							| 13 |  | fvex |  | 
						
							| 14 | 11 12 1 13 | ovmpo |  | 
						
							| 15 | 9 10 14 | sylancl |  | 
						
							| 16 |  | 1elunit |  | 
						
							| 17 |  | eqidd |  | 
						
							| 18 | 11 17 1 13 | ovmpo |  | 
						
							| 19 | 9 16 18 | sylancl |  | 
						
							| 20 | 2 3 3 8 15 19 | ishtpyd |  |