using System; using SCG = System.Collections.Generic; public delegate S Fun<R,S> (R r); public interface IIndexedSorted<T> { IIndexedSorted<V> Map<V> (Fun<T,V> mapper); } public class GuardedIndexedSorted<T> : IIndexedSorted<T> { IIndexedSorted<T> indexedsorted; public IIndexedSorted<V> Map<V> (Fun<T,V> m) { return indexedsorted.Map (m); } } class X { public static void Main () { } }