Document Types > Integrating the Equation Editor > Adding Equation Support to DITA Document Types > Adding Equation Support to a DITA DTD
  
Adding Equation Support to a DITA DTD
To support equations in a DITA DTD, you must integrate the atieqn-d domain into your DTD. The following files support this domain:
Arbortext Equation Domain files
File Name
Public ID
Description
atieqnDomain.ent
-//Arbortext//ENTITIES DITA Arbortext Equation Domain//EN
Declares entities for the domain.
atieqnDomain.mod
-//Arbortext//ELEMENTS DITA Arbortext Equation Domain//EN
Declares the equation and inlineequation elements and includes atimathns.dtd.
These files are located in the following directory:
Arbortext-path\entities
You integrate the domain into your DTD using the process defined in the DTD document-type shell: Coding requirements topic in the OASIS Darwin Information Typing Architecture (DITA) Version 1.2 standard. Follow these steps to integrate the domain into your DTD:
1. Include the atieqnDomain.ent file where other domain entities are included:
<!-- ============================================================= -->
<!-- DOMAIN ENTITY DECLARATIONS -->
<!-- ============================================================= -->
<!ENTITY % atieqn-d-dec
PUBLIC "-//Arbortext//ENTITIES DITA Arbortext Equation Domain//EN"
"atieqnDomain.ent"
>%atieqn-d-dec;
2. Integrate the domain extensions to the foreign element:
<!-- ============================================================= -->
<!-- DOMAIN EXTENSIONS -->
<!-- ============================================================= -->
<!ENTITY % foreign "foreign |
%atieqn-d-foreign;
">
3. Add the domain to the included-domains entity:
<!-- ============================================================= -->
<!-- DOMAINS ATTRIBUTE OVERRIDE -->
<!-- ============================================================= -->
<!ENTITY included-domains
"&concept-att;
&glossentry-att;
&glossgroup-att;
&reference-att;
&task-att;
&hi-d-att;
&ut-d-att;
&indexing-d-att;
&hazard-d-att;
&abbrev-d-att;
&pr-d-att;
&sw-d-att;
&ui-d-att;
&taskbody-constraints;
&atieqn-d-att;
4. Include the element definition module:
<!-- ============================================================= -->
<!-- DOMAIN ELEMENT INTEGRATION -->
<!-- ============================================================= -->
<!ENTITY % atieqn-d-def
PUBLIC "-//Arbortext//ELEMENTS DITA Arbortext Equation Domain//EN"
"atieqnDomain.mod"
>%atieqn-d-def;