% Square triangular matrices have the following properties.
% Property 1
A = [2 0 0; -3 1 0; -1 1 2]
B = [4 0 0; 1 2 0; 1 -2 1]
A * B

% Property 2
E = eye(3)
E(3,:) = E(3,:) + 4 * E(1,:)
E = eye(3)
E(1,:) = E(1,:) + 3 * E(2,:)

% Property 3
E = eye(3)
E(3,:) = 5 * E(3,:)

% Property 4
A = [2 0 0; -3 1 0; -1 1 2]
C = inv(A)
A * C
C * A
