
theorem Th28:
  for L being non empty reflexive RelStr, A being Subset of L
  holds A in sigma L implies A in xi L
proof
  let L be non empty reflexive RelStr, A be Subset of L;
  assume
A1: A in sigma L;
  the topology of ConvergenceSpace Scott-Convergence L c= the topology of
  ConvergenceSpace lim_inf-Convergence L by Th21,Th22;
  hence thesis by A1;
end;
