When a child is in the instance list it must have a parent
If a child object is in the instance it must have a parent in the instance list that can be associated with that has the same structural key.
If one does not exist an error message will be displayed at some stage, probably when the instance list needs to be visualized as tree control.
For example, if an EMPLOYEE, identified by the fully key ADM-0-01-0-A1001, needs to be visualized in a Visual LANSA tree then a search is made for its parent SECTION.
This is done by looking, using the AKey1-NKey1-AKey2-NKey2-AKey3-NKey3-AKey4-NKey5-AKey5-NKey5 structured key, first for SECTIONS-ADM (which would not found), then SECTIONS-ADM-0 (which would also not be found) then SECTIONS-ADM-0-01, which would be found, thus identifying the parent correctly.