program setExample (input, output);

type CharSetType = set of char;

const EMPTY = [];

VOWELS = ['A','E','I','O','U'];

var current: char;

set1, set2 : CharSetType;

begin

set1 := EMPTY;

set2 := Vowels;

set1 := set1 + set2;

if ('A' in set1) then

writeln (' A is in set1 ')

else

writeln (' A is not in set1');

set1 := set1 - ['A'];

if ('A' in set1) then

writeln (' A is in set1 ')

else

writeln (' A is not in set1');

end.