function M3 = symdiff_dfsa(M1,M2)
% M3 is the symmetric difference of M1 and M2
% see str2dfsa.m for basic dfsa definitions

notM2 = negate_fsa(M2);
M1lessM2 = intersect_dfsa(M1,notM2);
%M1lessM2 = minimize_dfsa(M1lessM2);
notM1 = negate_fsa(M1);
M2lessM1 = intersect_dfsa(notM1,M2);
%M2lessM1 = minimize_dfsa(M2lessM1);
M3 = union_dfsa(M1lessM2,M2lessM1);

return