descendant_of/2
descendant_of(+Obj, ?Class)
object
atom
Obj is an instance of Class or of a descendant of Class.
instantiation_error
Obj is unbound.
type_error
Object is not a valid object.
class_ancestor/2, class_of/2, class_superclass/2
class_ancestor/2
class_of/2
class_superclass/2