// This is one implementation of the abstract class PlugInForm as defined 
//  in MyPlugIn.dll .
// Compile with the command line:
//  csc /t:library MPIPsychiatrist.cs /r:MyPlugIn.dll
using System;
public class MPIFreud : PlugInForm
{
  public override void WhatIsPI()
  {
    Console.WriteLine("You desire your mother don't you?");
  }
}

public class MPIJung : PlugInForm
{
  public override void WhatIsPI()
  {
    Console.WriteLine("Why do you think you asked that question?");
  }
}