<!ELEMENT SystemDefinition (systemModel?, build?)>

 <!ATTLIST SystemDefinition

  name CDATA #REQUIRED

  schema CDATA #REQUIRED>

 <!ELEMENT systemModel (layer+)>

 <!ELEMENT layer (logicalset* | module*)*>

 <!ATTLIST layer

  name CDATA #REQUIRED

  levels CDATA #IMPLIED

  span CDATA #IMPLIED>

 <!ELEMENT logicalset (logicalsubset* | module* | unit* | package* | prebuilt*)*>

 <!ATTLIST logicalset name CDATA #REQUIRED>

 <!ELEMENT logicalsubset (module* | unit* | package* | prebuilt*)*>

 <!ATTLIST logicalsubset name CDATA #REQUIRED>

 <!ELEMENT module (component* | unit* | package* | prebuilt*)*>

 <!ATTLIST module

  name CDATA #REQUIRED

  level CDATA #IMPLIED>

 <!ELEMENT component (unit* | package* | prebuilt*)*>

 <!ATTLIST component name CDATA #REQUIRED>

 <!ELEMENT unit EMPTY>

 <!ATTLIST unit

  unitID ID #REQUIRED

  name CDATA #REQUIRED

  mrp CDATA #REQUIRED

  filter CDATA #IMPLIED

  bldFile CDATA #REQUIRED

  priority CDATA #IMPLIED

  contract CDATA #IMPLIED

  proFile CDATA #IMPLIED

  qmakeArgs CDATA #IMPLIED>

 <!ELEMENT package EMPTY>

 <!ATTLIST package

  name CDATA #REQUIRED

  mrp CDATA #REQUIRED

  filter CDATA #IMPLIED

  contract CDATA #IMPLIED>

 <!ELEMENT prebuilt EMPTY>

 <!ATTLIST prebuilt

  name CDATA #REQUIRED

  version CDATA #REQUIRED

  late (Y|N) #IMPLIED

  filter CDATA #IMPLIED

  contract CDATA #IMPLIED>

 <!ELEMENT build (option* | target+ | targetList+ | unitList+ | configuration+)*>

 <!ELEMENT unitList (unitRef+)>

 <!ATTLIST unitList

  name ID #REQUIRED

  description CDATA #REQUIRED>

 <!ELEMENT unitRef EMPTY>

 <!ATTLIST unitRef unit IDREF #REQUIRED>

 <!ELEMENT targetList EMPTY>

 <!ATTLIST targetList

  name ID #REQUIRED

  description CDATA #REQUIRED

  target IDREFS #REQUIRED>

 <!ELEMENT target EMPTY>

 <!ATTLIST target

  name ID #REQUIRED

  abldTarget CDATA #REQUIRED

  description CDATA #REQUIRED>

 <!ELEMENT option EMPTY>

 <!ATTLIST option

  name ID #REQUIRED

  abldOption CDATA #REQUIRED

  description CDATA #REQUIRED

  enable (Y | N | y | n) #REQUIRED>

 <!ELEMENT configuration (unitListRef+ | layerRef+ | task+)*>

 <!ATTLIST configuration

  name ID #REQUIRED

  description CDATA #REQUIRED

  filter CDATA #REQUIRED>

 <!ELEMENT task ( unitListRef* , (buildLayer | specialInstructions))>

 <!ELEMENT unitListRef EMPTY>

 <!ATTLIST unitListRef unitList IDREF #REQUIRED>

 <!ELEMENT layerRef EMPTY>

 <!ATTLIST layerRef layerName CDATA #REQUIRED>

 <!ELEMENT buildLayer EMPTY>

 <!ATTLIST buildLayer

  command CDATA #REQUIRED

  targetList IDREFS #IMPLIED

  unitParallel (Y | N | y | n) #REQUIRED

  targetParallel (Y | N | y | n) #IMPLIED>

 <!ELEMENT specialInstructions EMPTY>

 <!ATTLIST specialInstructions

  name CDATA #REQUIRED

  cwd CDATA #REQUIRED

  command CDATA #REQUIRED>