|
forwardDifference(x(1), n) := forwardDifferenceHelper(x, n, [x]);
|
|
|
|
forwardDifferenceHelper(x(1), n, result(2)) :=
|
|
let
|
|
difference := tail(x) - x[1 ... size(x) - 1];
|
|
in
|
|
result when n = 0 or size(x) = 1 else
|
|
forwardDifferenceHelper(difference, n - 1, result ++ [difference]);
|