External module in the base Suite that is named in the Suite Module of Modules (%modules.ent;) and then called from the Book Tag Set (or Collection Tag Set) to set up the namespaces and parameter entities for the MathML elements
This module then calls the MathML DTD to include the MathML elements in this Tag Set.
<!ENTITY % mathmlsetup.ent PUBLIC "-//NLM//DTD Archiving and Interchange DTD Suite MathML Setup Module v3.0 20080202//EN" "mathmlsetup3.ent" >
modules3.ent