using System;
using System.Collections.Generic;

class Program{

  public delegate double NumericFunction(double d);   

  public static void Main(){

    List<NumericFunction> equivalentFunctions = 
       new List<NumericFunction>(){
         delegate (double d){return d*d*d;},
         (double d) => {return d*d*d;},
         (double d) => d*d*d,
         (d) => d*d*d,
         d => d*d*d
      };

    foreach(NumericFunction nf in equivalentFunctions)
       Console.WriteLine("NumericFunction({0}) = {1}", 5, nf(5));
  }

}