function M = union_nfsas(MM)
% M is the nfsa-union of MM = {M1,M2,...}
% see str2nfsa.m for basic nfsa definitions

nQ = 0;
for j=1:length(MM)
  nQ = nQ + length(MM{j}.Q);
end
nQ = nQ + 1;

M = MM{1};
ft = fsa_type(M);
if (ft=='d')
  M = d2nfsa(M);
end

M.Q = 1:nQ;
M.q0 = 1;
M3.F = [];

shift = 1;
for j=1:length(MM)
  Mj = MM{j};
  ft = fsa_type(Mj);
  if (ft=='d')
    Mj = d2nfsa(Mj);
  end
  M.F = union(M.F,Mj.F+shift);
  R = nfsa_delta(M,1,'@');
  M = set_ndelta(M,[1],['@'],{union(R,Mj.q0+shift)});
  for q = Mj.Q
    for s = Mj.ALF
      R = nfsa_delta(Mj,q,s);
      M = set_ndelta(M,[q+shift],[s],{R+shift});
    end
  end
  shift = shift + length(Mj.Q);
end

return