% ``A`` -- The n-by-n coefficient matrix of the system.
%
% ``b`` -- An n-by-1 vector; the right-hand side of the system.
%
% ``x0`` -- An n-by-1 vector; an initial guess to the solution.
%
% ``A`` -- The n-by-n coefficient matrix of the system.
%
% ``b`` -- An n-by-1 vector; the right-hand side of the system.
%
% ``x0`` -- An n-by-1 vector; an initial guess to the solution.
%