function [b,u] = randstrinpt(M)
% returns a random string accepted by pt-lang M

X0 = simple_paths(M);

RR = {};
for i=1:length(X0)
  if run_dfsa(M,X0{i})
    RR{end+1} = spath2cell(M,X0{i});
  end
end

if empty_fsa(M)
  b = 0;
  u = '';
else
  b = 1;
  x = randel(RR);
  x = x{1};
  u = sample_from_sp(x,0);
end

return