For solving systems like
A1 x + B1 y = a1
A2 x + B2 y = a2
where x, y, a1, a2 are vectors and A1, A2, B1, B2 matrices. Takes any number of vectors, matrices, as long as the system of equations are consistent. Use solve_sparse_system for sparse systems.
See name == "main" part of slsi.py for examples.