function haromszog(a)
    [n d] = size(a)
    h = 1;
    for i = 1 : n
        for j = 1 : (i - 1)
            if a(i, j) ~= 0; h = 0; break; end
        end
        if h == 0; break; end
    end
    if h == 0; fprintf('Nem felso haromszog matrix.\n')
    else; fprintf('Felso haromszog matrix.\n'); end
end