STEPMod DTD for EXPRESS

The DTD used in the STEP Modules Repository as follows. Only the structure of EXPRESS schemas is supported. Any algorithms are simply represented as text (i.e. #PCDATA)

<!--
     $Id: express_model.dtd,v 1.14 2003/07/18 21:50:20 thendrix Exp $
                                                                   -->
<!-- EXPRESS MODEL DECLARATION MODULE -->

<!-- This set of declarations defines the EXPRESS-2 Model as of the
     date shown in the Formal Public Identifier (FPI) for this entity.

     This set of declarations may be referred to using a public external
     entity declaration and reference as shown in the following two lines:

<!ENTITY % express.model PUBLIC "-//TC184 SC4//DTD EXPRESS Model 20010901">
%express.model;

     If the parameter entity description.content used within this set 
     of declarations is to be given non-default values, the appropriate 
     declaration should be given before calling in this package 
     (i.e., before the "%express.model;" reference).
-->

<!-- This file was developed by Eurostep and supplied to NIST under contract.
     Authors:
	Rob Bodington
	David Price
	Nigel Shaw
	Phil Spiby
     Reviewed by:
	Josh Lubell
-->


<!--                    underlying type                            -->
<!ENTITY % underlying
                       "aggregate*, (typename | builtintype )"
                                                                     >


<!ENTITY % description.content "#PCDATA">

<!-- Attributes for source control software like RCS or CVS             -->
<!-- The rcs attributes are keywords for RCS source control systems     -->
<!--    rcs.date      $Date: 2003/07/18 21:50:20 $                      -->
<!--    rcs.revision  $Revision: 1.14 $                                  -->
<!--    reference is the source of the schema, e.g. ISO 10303-41        -->
<!ELEMENT express (description?, application?, schema+)>
<!ATTLIST express
	language_version (1 | 2 | 3) "1" 
        rcs.date CDATA #REQUIRED 
	rcs.revision CDATA #REQUIRED
        reference  CDATA #IMPLIED
        description.file CDATA #IMPLIED
>


<!ELEMENT description (%description.content;)*>

<!ELEMENT application EMPTY>
<!ATTLIST application
	name CDATA #IMPLIED
	owner CDATA  #IMPLIED
	url CDATA  #IMPLIED
	version CDATA  #IMPLIED
	source CDATA #REQUIRED
>


<!ELEMENT schema (description?, interface*, constant*, (entity | function | procedure | rule | subtype.constraint | type)*, graphic.element?)>

<!ATTLIST schema
	name NMTOKEN #REQUIRED
        version NMTOKEN #IMPLIED
>

<!ELEMENT interface (interfaced.item*, described.item*)>
<!ATTLIST interface
	kind (use | reference) "use"
	schema NMTOKEN #REQUIRED
>
<!ELEMENT interfaced.item EMPTY>
<!ATTLIST interfaced.item
	name NMTOKEN #REQUIRED
	alias NMTOKEN #IMPLIED
>

<!-- 
  A description of any item in the interface. In other words the
  documentation of an imported construct.         
  item is the name of the imported construct
  attribute is only used if the imported construct is an entity in whihc
  case, item is the name of the entty and item is the name of the attribute
 -->
<!ELEMENT described.item (description?)>
<!ATTLIST described.item
	item NMTOKEN #REQUIRED
        attribute NMTOKEN #IMPLIED
	kind (ENTITY | TYPE | ATTRIBUTE | FUNCTION | PROCEDURE | CONSTANT ) "ENTITY">


<!ELEMENT constant (description?, %underlying;)>
<!ATTLIST constant
	name NMTOKEN #REQUIRED
	expression CDATA #REQUIRED
>

<!ELEMENT type (description?, aggregate*, (typename | builtintype | enumeration | select), where*, graphic.element?)>
<!ATTLIST type
	name NMTOKEN #REQUIRED
>

<!ELEMENT typename EMPTY>
<!ATTLIST typename
	name NMTOKEN #REQUIRED
>

<!ELEMENT builtintype (graphic.element?)>
<!ATTLIST builtintype
	type (BINARY | BOOLEAN | GENERIC | GENERICENTITY | INTEGER | LOGICAL | NUMBER | REAL | STRING) "STRING"
	width CDATA #IMPLIED
	fixed (YES | NO) "NO"
	precision CDATA #IMPLIED
	typelabel NMTOKEN #IMPLIED
>
<!-- Width to allow for Binary and string -->
<!-- Fixed to allow for Binary and string -->
<!-- Precision to allow for REAL -->
<!ELEMENT aggregate EMPTY>
<!ATTLIST aggregate
	type (AGGREGATE | ARRAY | BAG | LIST | SET) "SET"
	optional (YES | NO) "NO"
	unique (YES | NO) "NO"
	lower CDATA #IMPLIED
	upper CDATA #IMPLIED
	typelabel NMTOKEN #IMPLIED
>
<!ELEMENT select (graphic.element?)>
<!ATTLIST select
	extensible (YES | NO) "NO"
	genericentity (YES | NO) "NO"
	basedon NMTOKEN #IMPLIED
	selectitems NMTOKENS #IMPLIED
>
<!ELEMENT graphic.element  EMPTY>
<!ATTLIST graphic.element
        image CDATA #IMPLIED
	page CDATA #REQUIRED
	xcoord CDATA #IMPLIED
	ycoord CDATA #IMPLIED
>
<!ELEMENT enumeration (graphic.element?)>
<!ATTLIST enumeration
	extensible (YES | NO) "NO"
	basedon NMTOKEN #IMPLIED
	items NMTOKENS #IMPLIED
>
<!ELEMENT entity (description?, explicit*, derived*, inverse*, unique*, where*, graphic.element?)>
<!ATTLIST entity
	name NMTOKEN #REQUIRED
	abstract.entity (YES | NO) "NO"
	abstract.supertype (YES | NO) "NO"
	supertypes NMTOKENS #IMPLIED
	super.expression CDATA #IMPLIED
>
<!ELEMENT explicit (description?, %underlying;, redeclaration?)>
<!ATTLIST explicit
	name NMTOKEN #REQUIRED
	optional (YES | NO) "NO"
>
<!ELEMENT derived (description?, %underlying;, redeclaration?)>
<!ATTLIST derived
	name NMTOKEN #REQUIRED
	expression CDATA #REQUIRED
>
<!ELEMENT inverse (description?, inverse.aggregate?, redeclaration?)>
<!ATTLIST inverse
	name NMTOKEN #REQUIRED
	entity NMTOKEN #REQUIRED
	attribute NMTOKEN #REQUIRED
>
<!ELEMENT inverse.aggregate EMPTY>
<!ATTLIST inverse.aggregate
 	type (BAG | SET) "SET"
	lower CDATA #IMPLIED
	upper CDATA #IMPLIED
>
<!ELEMENT redeclaration EMPTY>
<!ATTLIST redeclaration
	entity-ref NMTOKEN #REQUIRED
	old_name NMTOKEN #IMPLIED
>
<!ELEMENT where (description?)>
<!ATTLIST where
	label NMTOKEN #IMPLIED
	expression CDATA #IMPLIED
>
<!--<!ELEMENT unique (description?, unique.attribute)>-->
<!ELEMENT unique (description?, unique.attribute+)>
<!ATTLIST unique
	label NMTOKEN #IMPLIED
>
<!ELEMENT unique.attribute EMPTY>
<!ATTLIST unique.attribute
	entity-ref NMTOKEN #IMPLIED
	attribute NMTOKEN #REQUIRED
>
<!ELEMENT subtype.constraint (description?, graphic.element?)>
<!ATTLIST subtype.constraint
	name NMTOKEN #REQUIRED
	entity NMTOKEN #REQUIRED
	abstract.supertype (YES | NO) "NO"
	totalover NMTOKENS #IMPLIED
	super.expression CDATA #IMPLIED
>

<!ELEMENT function (description?, parameter*, %underlying;, algorithm)>
<!ATTLIST function
	name NMTOKEN #REQUIRED
>

<!ELEMENT parameter (description?, %underlying;)>
<!ATTLIST parameter
	name NMTOKEN #REQUIRED
>

<!ELEMENT procedure (description?, parameter*, algorithm?)>
<!ATTLIST procedure
	name NMTOKEN #REQUIRED
>

<!ELEMENT rule (description?, algorithm?, where+)>
<!ATTLIST rule
	name NMTOKEN #REQUIRED
	appliesto NMTOKENS #REQUIRED
>


<!ELEMENT algorithm (#PCDATA)>