Permitted and Not permitted class combinations

public class ZClass<T>

{

}

public class XClass<T> : ZClass<T>

{

}

public class BClass<Y>

{

}

public class AClass<Z> : BClass<int>

{

}

public class YClass : ZClass<int>

{

}

/*

public class AClass<Z> : BClass<Y>

{

[ illegal ]

}

public class YClass: ZClass<T>

{

[ illegal ]

}

*/

Ref:
http://shiman.wordpress.com/2008/07/15/c-net-generics-inheritance/