public class Map <b>
{
     b x;

    public a Fold1 <a> (a ini)
    {
      return ini;
    } 

    public c Fold<c> (c ini)
    {
       Fold1 <b> (x);
       return   ini;
    }
}


public class LocalContext
{
    Map <string> locals = new Map <string> ();

    public a Fold <a> (a acc)
    {
      return locals.Fold (acc);
    }
}

class M {
  public static void Main () {
     LocalContext x = new LocalContext ();
     x.Fold ("a" );
  }
}