delegate-based polymorphism without generics

delegates.cs

using System.Collections;

namespace DelegateExample
{
    class Program
    {
        static void Main()
        {
            var list1 = new ArrayList { 1, 2, 3 };
            var list2 = new ArrayList { 1, 3, 2 };
            bool sequenceEqual = CompareList(list1, list2, (a, b) => (int)a == (int)b);

            int duplicate = 0;
            bool hasNoDuplicates = CompareList(list1, list2, (a, b) => {
                if ((int)a != (int)b) return true;
                duplicate = (int)a;
                return false;
            });
        }

        delegate bool Checker(object a, object b);

        static bool CompareList(ArrayList listA, ArrayList listB, Checker check)
        {
            if (listA.Count != listB.Count) return false;
            for (int i = 0; i < listB.Count; i++)
            {
                if (!check(listA[i], listB[i]))
                {
                    return false;
                }
            }
            return true;
        }
    }
}