function NFSA = d2nfsa(DFSA)
% convets a DFSA to equivalent NFSA (trivial)

% 1. a NFSA is defined by
% 2. an alphabet ALF
% 3. a set of states Q 
% 4. a set of the start states Q0
% 5. a set of accepting states F \subste {1,2,3,...,Q}
% 6. a function delta : (q,s) \mapsto Q'
%    where Q' subset Q, s\in ALF_in; q'\in Q

global ALF
NFSA.ALF = ['@' DFSA.ALF];
% the character @ stands for the epsilon-char

NFSA.Q = DFSA.Q;
NFSA.q0 = [DFSA.q0];
NFSA.F = DFSA.F;

NFSA = init_ndelta(NFSA);
for q1=DFSA.Q
  for s=DFSA.ALF
    q2 = dfsa_delta(DFSA,q1,s);
    NFSA = set_ndelta(NFSA,[q1],[s],{[q2]});
  end
end

if 0
  DS = deadstates_fsa(NFSA);
  for q=NFSA.Q
    for s=NFSA.ALF
      R = nfsa_delta(NFSA,q,s);
      R = setdiff(R,DS);
      NFSA = set_ndelta(NFSA,[q],[s],{R});
    end
  end
  NFSA.Q = setdiff(NFSA.Q,DS);
  NFSA = compact_names(NFSA);
end
return