I’m not sure that this categoly is proper to post, but the function “invert” doesn’t work in this case. I need your help!

I executed the following code. It calculates inverse of a matrix A and multiple it by A to confirm if it’s correct.

```
import Blender as B
import Blender.Mathutils as BM
BVec = BM.Vector
BMat = BM.Matrix
lcAMat = BMat([1,1], [-1,0])
lcBVec = BVec([1,1])
print lcAMat, "AMat"
lcAInv = lcAMat.invert()
print lcAInv, "AInv"
lcACopy = BMat([1,1], [-1,0])
print lcAInv*lcACopy, "1?"
```

I got the following result in which A^-1 * A is not equal to unit matrix. That’s the problem.

I have confirmed what A^-1 is by calculating with kind of software of computer algebra system (CAS) as follows.

According to CAS, the correct answer of A^-1 is [[0,-1],[1,1]] while it’s [[0,1],[-1,1]] in Blender. Please let me know what my mistake is in the code.