| Step | Hyp | Ref | Expression | 
						
							| 1 |  | mrcfval.f |  | 
						
							| 2 |  | fvssunirn |  | 
						
							| 3 | 2 | sseli |  | 
						
							| 4 |  | unieq |  | 
						
							| 5 | 4 | pweqd |  | 
						
							| 6 |  | rabeq |  | 
						
							| 7 | 6 | inteqd |  | 
						
							| 8 | 5 7 | mpteq12dv |  | 
						
							| 9 |  | df-mrc |  | 
						
							| 10 |  | mreunirn |  | 
						
							| 11 |  | mrcflem |  | 
						
							| 12 | 10 11 | sylbi |  | 
						
							| 13 |  | fssxp |  | 
						
							| 14 | 12 13 | syl |  | 
						
							| 15 |  | vuniex |  | 
						
							| 16 | 15 | pwex |  | 
						
							| 17 |  | vex |  | 
						
							| 18 | 16 17 | xpex |  | 
						
							| 19 |  | ssexg |  | 
						
							| 20 | 14 18 19 | sylancl |  | 
						
							| 21 | 8 9 20 | fvmpt3 |  | 
						
							| 22 | 3 21 | syl |  | 
						
							| 23 |  | mreuni |  | 
						
							| 24 | 23 | pweqd |  | 
						
							| 25 | 24 | mpteq1d |  | 
						
							| 26 | 22 25 | eqtrd |  | 
						
							| 27 | 1 26 | eqtrid |  |