
mat = [ 1, 0, 0;
        0, 1, 0;
       -1, -1, 0];
%mat = [ 2, 0, 0;
%        1, 2, 1;
%        0, 0, 2;
%       -1, 2, 3 ];

[E,B] = null_and_complement_null(mat);
E
B
