<?xml version="1.0"?>
<out xmlns:set="http://exslt.org/sets">
    Containing i and e:
    Vienna;
    Berlin;
          
    Containing i and no e:
    Paris;
    Madrid;
    Calais;
      
    Containing e and no i:
    Barcelona;
    Hannover;
     
    Containing i:
    Paris;
    Madrid;
    Vienna;
    Calais;
    Berlin;
     
    Empty set:
          
    Empty set:
      
    Empty set:
    </out>