LINQPad snippet that declares two string arrays, spits out their mutually exclusive parts.

string-set-vs-set.cs

var set1 = new string[]{"a","b","c","d"};
var set2 = new string[]{"a","e","i","o","u"};

var q = set1.Except(set2);

Console.WriteLine(q.Count());
Console.WriteLine("");
foreach(string s in q)
{
Console.WriteLine(s);
}
Console.WriteLine("");

var r = set2.Except(set1);

Console.WriteLine(r.Count());
Console.WriteLine("");
foreach(string s in r)
{
Console.WriteLine(s);
}
Console.WriteLine("");