static void Main()
{
List <string> left = new List <string> {
"Alice", "Charles", "Derek"
};
List <string> right = new List <string> {
"Bob", "Charles", "Ernie"
};
EnumerableExtensions.CompareSortedCollections(left, right, StringComparer.CurrentCultureIgnoreCase,
s => Console.WriteLine("Left: " + s), s => Console.WriteLine("Right: " + s), (x, y) => Console.WriteLine("Both: " + x + y));
}