using System;

// A generic subclass of a non-generic superclass.
class SomeGenericSet1<T>: IntSet{
  // ...
}

// A generic subclass of a constructed superclass
class SomeGenericSet2<T>: Set<int>{
  // ...
}

// A generic subclass of a generic superclass
// The most realistic case
class SpecializedSet<T>: Set<T>{
  // ...
}

// A non-generic subclass of a generic superclass
// Illegal. Compile-time error:
// The type or namespace name 'T' could not be found
class Set: Set<T>{
  // ...
}