child_type

In Deriscope terminology, a child type is a Deriscope Type C that has the following relationship to a given type T.
T is a parent type of C.
In case the concept of parent type is not yet defined, the required relationship can be also described as:
The family of all potential member Deriscope Objects of C is a subset of the respective family of T.

For example, the type Tradable is a child type of the type Currency as the family of all Tradable objects icludes all Currency objects.