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            _____    _    _      ___      _  _   
  ____     |  ___|| | \  / ||   / _ \\   | \| || 
 |    \\   | ||__   |  \/  ||  | / \ ||  |  ' || 
 | [] ||   | ||__   | .  . ||  | \_/ ||  | .  || 
 |  __//   |_____|| |_|\/|_||   \___//   |_|\_|| 
 |_|`-`    `-----`  `-`  `-`    `---`    `-` -`  
 `-`

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Text this: Closed left-r.e. sets