|A :=  4 4 reshape 1 1 1 1 2 4 8 16 3 9 27 81 4 16 64 256
=1  1  1   1
=2  4  8  16
=3  9 27  81
=4 16 64 256
|B := inverse A

|A innerproduct B
=1.        0.     8.3e-17     -2.9e-16
=1.3e-15   1.     -4.4e-16    -3.3e-16
=0.        0.      1.         4.4e-16
=0.        0.      0.         1.