| Step | Hyp | Ref | Expression | 
						
							| 1 |  | efmnd.1 |  | 
						
							| 2 |  | efmnd.2 |  | 
						
							| 3 |  | efmnd.3 |  | 
						
							| 4 |  | efmnd.4 |  | 
						
							| 5 |  | elex |  | 
						
							| 6 |  | ovexd |  | 
						
							| 7 |  | id |  | 
						
							| 8 |  | id |  | 
						
							| 9 | 8 8 | oveq12d |  | 
						
							| 10 | 9 2 | eqtr4di |  | 
						
							| 11 | 7 10 | sylan9eqr |  | 
						
							| 12 | 11 | opeq2d |  | 
						
							| 13 |  | eqidd |  | 
						
							| 14 | 11 11 13 | mpoeq123dv |  | 
						
							| 15 | 14 3 | eqtr4di |  | 
						
							| 16 | 15 | opeq2d |  | 
						
							| 17 |  | simpl |  | 
						
							| 18 |  | pweq |  | 
						
							| 19 | 18 | sneqd |  | 
						
							| 20 | 19 | adantr |  | 
						
							| 21 | 17 20 | xpeq12d |  | 
						
							| 22 | 21 | fveq2d |  | 
						
							| 23 | 22 4 | eqtr4di |  | 
						
							| 24 | 23 | opeq2d |  | 
						
							| 25 | 12 16 24 | tpeq123d |  | 
						
							| 26 | 6 25 | csbied |  | 
						
							| 27 |  | df-efmnd |  | 
						
							| 28 |  | tpex |  | 
						
							| 29 | 26 27 28 | fvmpt |  | 
						
							| 30 | 5 29 | syl |  | 
						
							| 31 | 1 30 | eqtrid |  |