direct container


In Deriscope terminology, a
Deriscope Type A is called a direct container of a type B if A is a container of B and no other type T exists in between.

It follows that then B is a
direct subtype of A

As an example, the following two statements hold:
1) The type
Tradable is a direct container of the type Bond
2) The type
Tradable is not a direct container of the type Zero Bond