the ID is not NIL and does not pertain to a primitive item.
Return the number of children that it has.
(Int) = NBS_GET_CHILDREN
ID = INTEGER (Given)
Identifier of the item whose
number of children is to be got.
CHILDREN = INTEGER (Returned)
Number of children.
STATUS = INTEGER (Given and returned)
The global status. Possible return values
|Parent is primitive|