inversion: You should see (2,1,0,0)
ny=0   2.00   1.00   0.00   0.00
ny=1   2.00   1.00   0.00   0.00
ny=0   2.00   1.00   0.00   0.00   0.00
ny=1   2.00   1.00   0.00   0.00   0.00

Convolution theorem: Proportional to (0,2,-1,-1,0,0,0,0)
ny=0   0.00   0.89  -0.45  -0.45   0.00
ny=1   0.00   0.89  -0.45  -0.45   0.00
ny=0   0.00   0.82  -0.41  -0.41   0.00   0.00
ny=1   0.00   0.82  -0.41  -0.41   0.00   0.00

Delay tests:
In              11.0   12.0   13.0   14.0   15.0   16.0   17.0
Out  n=7 ny=0   16.0   17.0   11.0   12.0   13.0   14.0   15.0
Out  n=7 ny=1  -16.0  -17.0   11.0   12.0   13.0   14.0   15.0
Out  n=6 ny=0  -15.0  -16.0   11.0   12.0   13.0   14.0
Out  n=6 ny=1   15.0   16.0   11.0   12.0   13.0   14.0

Derivative tests:
In             10.0  10.0  10.0  10.0  12.0  10.0  10.0  10.0  10.0
Out  n=9 ny=0  -0.7   0.8  -1.1   2.0   0.0  -2.0   1.1  -0.8   0.7
Out  n=9 ny=1  13.5  -5.1   2.0   0.7   0.0  -0.7  -2.0   5.1 -13.5
Out  n=8 ny=0  13.2  -5.7   3.5  -1.9   3.9  -6.6   7.6 -14.8
Out  n=8 ny=1   0.0   0.3  -0.8   1.9   0.0  -1.9   0.8  -0.3