| Step | Hyp | Ref | Expression | 
						
							| 1 |  | maxidlval.1 |  | 
						
							| 2 |  | maxidlval.2 |  | 
						
							| 3 |  | fveq2 |  | 
						
							| 4 |  | fveq2 |  | 
						
							| 5 | 4 1 | eqtr4di |  | 
						
							| 6 | 5 | rneqd |  | 
						
							| 7 | 6 2 | eqtr4di |  | 
						
							| 8 | 7 | neeq2d |  | 
						
							| 9 | 7 | eqeq2d |  | 
						
							| 10 | 9 | orbi2d |  | 
						
							| 11 | 10 | imbi2d |  | 
						
							| 12 | 3 11 | raleqbidv |  | 
						
							| 13 | 8 12 | anbi12d |  | 
						
							| 14 | 3 13 | rabeqbidv |  | 
						
							| 15 |  | df-maxidl |  | 
						
							| 16 |  | fvex |  | 
						
							| 17 | 16 | rabex |  | 
						
							| 18 | 14 15 17 | fvmpt |  |