| Step | Hyp | Ref | Expression | 
						
							| 1 |  | onovuni.1 |  | 
						
							| 2 |  | onovuni.2 |  | 
						
							| 3 |  | oveq2 |  | 
						
							| 4 |  | eqid |  | 
						
							| 5 |  | ovex |  | 
						
							| 6 | 3 4 5 | fvmpt |  | 
						
							| 7 | 6 | elv |  | 
						
							| 8 |  | oveq2 |  | 
						
							| 9 |  | ovex |  | 
						
							| 10 | 8 4 9 | fvmpt |  | 
						
							| 11 | 10 | elv |  | 
						
							| 12 | 11 | a1i |  | 
						
							| 13 | 12 | iuneq2i |  | 
						
							| 14 | 1 7 13 | 3eqtr4g |  | 
						
							| 15 | 2 11 7 | 3sstr4g |  | 
						
							| 16 | 14 15 | onfununi |  | 
						
							| 17 |  | uniexg |  | 
						
							| 18 |  | oveq2 |  | 
						
							| 19 |  | ovex |  | 
						
							| 20 | 18 4 19 | fvmpt |  | 
						
							| 21 | 17 20 | syl |  | 
						
							| 22 | 21 | 3ad2ant1 |  | 
						
							| 23 | 11 | a1i |  | 
						
							| 24 | 23 | iuneq2i |  | 
						
							| 25 | 24 | a1i |  | 
						
							| 26 | 16 22 25 | 3eqtr3d |  |