| Step | Hyp | Ref | Expression | 
						
							| 1 |  | fprodsub2cncf.k |  | 
						
							| 2 |  | fprodsub2cncf.a |  | 
						
							| 3 |  | fprodsub2cncf.b |  | 
						
							| 4 |  | fprodsub2cncf.f |  | 
						
							| 5 | 4 | a1i |  | 
						
							| 6 |  | eqid |  | 
						
							| 7 | 6 | cnfldtopon |  | 
						
							| 8 | 7 | a1i |  | 
						
							| 9 |  | eqid |  | 
						
							| 10 | 3 9 | sub2cncfd |  | 
						
							| 11 | 6 | cncfcn1 |  | 
						
							| 12 | 11 | a1i |  | 
						
							| 13 | 10 12 | eleqtrd |  | 
						
							| 14 | 1 6 8 2 13 | fprodcn |  | 
						
							| 15 | 5 14 | eqeltrd |  | 
						
							| 16 | 11 | a1i |  | 
						
							| 17 | 16 | eqcomd |  | 
						
							| 18 | 15 17 | eleqtrd |  |