%Inversarea unei matrice superior triunghiulare
function B = InvTriSup(A)
[n, n] = size(A);
for j = n : -1 : 1
    B(j, j) = 1 / A(j, j);
    for i = j - 1 : -1 : 1
        B(i,j)=-A(i,i+1:j)*B(i+1:j,j)/A(i,i);
    end
end