| Step | Hyp | Ref | Expression | 
						
							| 1 |  | pmapfval.b |  | 
						
							| 2 |  | pmapfval.l |  | 
						
							| 3 |  | pmapfval.a |  | 
						
							| 4 |  | pmapfval.m |  | 
						
							| 5 |  | elex |  | 
						
							| 6 |  | fveq2 |  | 
						
							| 7 | 6 1 | eqtr4di |  | 
						
							| 8 |  | fveq2 |  | 
						
							| 9 | 8 3 | eqtr4di |  | 
						
							| 10 |  | fveq2 |  | 
						
							| 11 | 10 2 | eqtr4di |  | 
						
							| 12 | 11 | breqd |  | 
						
							| 13 | 9 12 | rabeqbidv |  | 
						
							| 14 | 7 13 | mpteq12dv |  | 
						
							| 15 |  | df-pmap |  | 
						
							| 16 | 14 15 1 | mptfvmpt |  | 
						
							| 17 | 4 16 | eqtrid |  | 
						
							| 18 | 5 17 | syl |  |