| Step | Hyp | Ref | Expression | 
						
							| 1 |  | topontop |  | 
						
							| 2 |  | fvssunirn |  | 
						
							| 3 | 2 | sseli |  | 
						
							| 4 |  | unieq |  | 
						
							| 5 |  | unieq |  | 
						
							| 6 | 4 5 | oveqan12d |  | 
						
							| 7 |  | simpl |  | 
						
							| 8 | 4 | adantr |  | 
						
							| 9 | 8 | oveq1d |  | 
						
							| 10 |  | simpr |  | 
						
							| 11 | 9 10 | fveq12d |  | 
						
							| 12 | 7 11 | oveq12d |  | 
						
							| 13 | 6 12 | mpteq12dv |  | 
						
							| 14 |  | df-flf |  | 
						
							| 15 |  | ovex |  | 
						
							| 16 | 15 | mptex |  | 
						
							| 17 | 13 14 16 | ovmpoa |  | 
						
							| 18 | 1 3 17 | syl2an |  | 
						
							| 19 |  | toponuni |  | 
						
							| 20 | 19 | eqcomd |  | 
						
							| 21 |  | filunibas |  | 
						
							| 22 | 20 21 | oveqan12d |  | 
						
							| 23 | 20 | adantr |  | 
						
							| 24 | 23 | oveq1d |  | 
						
							| 25 | 24 | fveq1d |  | 
						
							| 26 | 25 | oveq2d |  | 
						
							| 27 | 22 26 | mpteq12dv |  | 
						
							| 28 | 18 27 | eqtrd |  |