| Step | Hyp | Ref | Expression | 
						
							| 1 |  | oveq1 |  |-  ( n = N -> ( n ^ ( x - 1 ) ) = ( N ^ ( x - 1 ) ) ) | 
						
							| 2 | 1 | oveq1d |  |-  ( n = N -> ( ( n ^ ( x - 1 ) ) - 1 ) = ( ( N ^ ( x - 1 ) ) - 1 ) ) | 
						
							| 3 | 2 | breq2d |  |-  ( n = N -> ( x || ( ( n ^ ( x - 1 ) ) - 1 ) <-> x || ( ( N ^ ( x - 1 ) ) - 1 ) ) ) | 
						
							| 4 | 3 | anbi2d |  |-  ( n = N -> ( ( x e/ Prime /\ x || ( ( n ^ ( x - 1 ) ) - 1 ) ) <-> ( x e/ Prime /\ x || ( ( N ^ ( x - 1 ) ) - 1 ) ) ) ) | 
						
							| 5 | 4 | rabbidv |  |-  ( n = N -> { x e. ( ZZ>= ` 4 ) | ( x e/ Prime /\ x || ( ( n ^ ( x - 1 ) ) - 1 ) ) } = { x e. ( ZZ>= ` 4 ) | ( x e/ Prime /\ x || ( ( N ^ ( x - 1 ) ) - 1 ) ) } ) | 
						
							| 6 |  | df-fppr |  |-  FPPr = ( n e. NN |-> { x e. ( ZZ>= ` 4 ) | ( x e/ Prime /\ x || ( ( n ^ ( x - 1 ) ) - 1 ) ) } ) | 
						
							| 7 |  | fvex |  |-  ( ZZ>= ` 4 ) e. _V | 
						
							| 8 | 7 | rabex |  |-  { x e. ( ZZ>= ` 4 ) | ( x e/ Prime /\ x || ( ( N ^ ( x - 1 ) ) - 1 ) ) } e. _V | 
						
							| 9 | 5 6 8 | fvmpt |  |-  ( N e. NN -> ( FPPr ` N ) = { x e. ( ZZ>= ` 4 ) | ( x e/ Prime /\ x || ( ( N ^ ( x - 1 ) ) - 1 ) ) } ) |