| Step | Hyp | Ref | Expression | 
						
							| 1 |  | isnacs.f |  | 
						
							| 2 |  | elfvex |  | 
						
							| 3 |  | elfvex |  | 
						
							| 4 | 3 | adantr |  | 
						
							| 5 |  | fveq2 |  | 
						
							| 6 |  | pweq |  | 
						
							| 7 | 6 | ineq1d |  | 
						
							| 8 | 7 | rexeqdv |  | 
						
							| 9 | 8 | ralbidv |  | 
						
							| 10 | 5 9 | rabeqbidv |  | 
						
							| 11 |  | df-nacs |  | 
						
							| 12 |  | fvex |  | 
						
							| 13 | 12 | rabex |  | 
						
							| 14 | 10 11 13 | fvmpt |  | 
						
							| 15 | 14 | eleq2d |  | 
						
							| 16 |  | fveq2 |  | 
						
							| 17 | 16 1 | eqtr4di |  | 
						
							| 18 | 17 | fveq1d |  | 
						
							| 19 | 18 | eqeq2d |  | 
						
							| 20 | 19 | rexbidv |  | 
						
							| 21 | 20 | raleqbi1dv |  | 
						
							| 22 | 21 | elrab |  | 
						
							| 23 | 15 22 | bitrdi |  | 
						
							| 24 | 2 4 23 | pm5.21nii |  |