let N = 16;
namespace FibArrays(N);
    col fixed ISLAST(i) { if i == N - 1 { 1 } else { 0 } };
    col witness unused;
    col witness x[2];
    col witness unused2;

    ISLAST * (x[1]' - 1) = 0;
    ISLAST * (x[0]' - 1) = 0;

    (1-ISLAST) * (x[0]' - x[1]) = 0;
    (1-ISLAST) * (x[1]' - (x[0] + x[1])) = 0;

    (unused - 1) * unused2 = 0;

    public out = x[1](N - 1);
