====== Parent sub-system and Root sub-system ======

====Parent sub-system====

In an hierarchy of [[Sub-system|sub-systems]], the parent sub-system of a [[Block|block]] or [[Sub-system|sub-system]] is the [[Sub-system|sub-system]] immediatly above it in the hierarchy.

{{forest_unit.png?200}} 

For instance, if the sub-system //Forest unit// contains sub-systems named //Forest, Berries, Mushrooms and Game//, then //Forest unit// is the parent sub-system of //Berries// sub-system.



{{parent_sub_system.png?500}}

==== Root sub-system ====

The top-level [[Sub-system|sub-system]] of a model. The [[ID|id]] of the root sub-system is blank, so that [[Block|blocks]] that belong to it have the same [[ID|id]] as [[Name|name]].

===== See also =====

  * [[ID|ID]]
  * [[Name|Name]]
  * [[Sub-system|Sub-system]]