What i am trying to do is excluding an matrix from another matrix without knowing if MatrixA was multiply by MatrixB. For example if we had

AxB=AB if i want to remove a i can just pass A inverse multiply by B to remove A. But my problem is, let say i do not have A and i pass some matrix

to a function that Take AB for example and pass an matrix exlusion of A. How can i tell that A is a actually part of AB.

Thanks

Actually i was wrong. It does not work. I guess it is not possible. From all the thing i try to do. Logically now that i think about it, it makes no sense.