I'm trying to solve an eigenvalue problem of the form: $\textbf{A}\vec{x}=\lambda \textbf{B}\vec{x}$, where A and B are square matrices, $\lambda$ are the eigenvalues and $\vec{x}$ the eigenfunctions.
I tried to use Eigensystem[{A,B}], but I got the following:
This was meant only to illustrate that the output was just the function and its arguments which are the matrices A and B. It didn't calculate anything.

This last image is meant to show how I created the matrices A and B. Basically, each of them are block matrices built by joining 4 blocks. Is my problem related to the fact that the output for matrices A and B are just the "matrixform" of something that Eigensystem cannot accept as an argument, therefore not calculating anything? Thank you for your attention.
