An XHTML + MathML + SVG Profile

1.  Introduction

This section is informative.

An XHTML+MathML+SVG profile integrates XHTML 1.1 [XHTML11], MathML 2.0 [MathML2] and SVG 1.1 [SVG11] together, using the XHTML Modularization Framework [XHTMLMOD]. This profile enables mixing XHTML, MathML and SVG in a same document using XML namespaces [XMLNS] mechanism, while allowing validation of such a mixed-namespace document. An XHTML 1.1 + MathML 2.0 + SVG 1.1 DTD driver is provided in section 2.1. The possibility of combining those modules written in XML Schema [XMLSchema] might be explored when XML Schemas for XHTML [XHTMLMODSchema] and others become available and mature.

This DTD driver can primarily be used for an XHTML document that contains MathML and SVG fragments, but it can also be used for an SVG document that contains XHTML and MathML fragments. An SVG fragment inside an XHTML document can contain another XHTML or MathML fragments, and that XHTML fragment can again contain another MathML or SVG fragments. There's no restriction on nesting levels.

Inside XHTML, MathML and SVG fragments are allowed basically anywhere inside the document body. Inside SVG, XHTML and MathML may be embedded through the foreignObject element (SVG 1.1 [SVG11], section 23.3). A sample document (MathML and SVG-enabled XHTML browsers only) shows features in XHTML 1.1 (ruby) and simple MathML and SVG examples, and a mixture of them using foreignObject, in the same document. On MathML and SVG-enabled XHTML browsers, mixed sample would be rendered like this:

This DTD driver can also be used as a basis for defining other profiles that combine some or all of XHTML, MathML and SVG. How to define new profiles using this DTD driver is explained in section 4.

<!-- ....................................................................... -->
<!-- XHTML 1.1 plus MathML 2.0 plus SVG 1.1 DTD  ........................... -->
<!-- URI: http://www.w3.org/2002/04/xhtml-math-svg/xhtml-math-svg.dtd
-->

<!-- XHTML 1.1 plus MathML 2.0 plus SVG 1.1 DTD

     This is a prototype extension of XHTML 1.1 incorporating MathML 2.0
     and SVG 1.1.

     Copyright 2002 World Wide Web Consortium
        (Massachusetts Institute of Technology, Institut National de
         Recherche en Informatique et en Automatique, Keio University).
         All Rights Reserved.

     Permission to use, copy, modify and distribute this DTD and its
     accompanying documentation for any purpose and without fee is hereby
     granted in perpetuity, provided that the above copyright notice and 
     this paragraph appear in all copies.  The copyright holders make no
     representation about the suitability of the DTD for any purpose.

     It is provided "as is" without expressed or implied warranty.

        Editors:    Murray M. Altheim <altheim@eng.sun.com> (XHTML modules)
                    David Carlisle <davidc@nag.co.uk> (MathML modules)
                    Jun Fujisawa <fujisawa.jun@canon.co.jp> (SVG modules)
                    Masayasu Ishikawa <mimasa@w3.org> (DTD driver)
        Revision:
          $Id: xhtml-math-svg.dtd,v 1.26 2002/08/08 12:33:40 mimasa Exp $

-->
<!-- This is the driver for an XHTML 1.1 plus MathML 2.0 plus SVG 1.1 DTD.
-->

<!-- Switches to include/ignore each vocabulary.
-->
<!ENTITY % XHTML.module  "INCLUDE" >
<!ENTITY % MATHML.module "INCLUDE" >
<!ENTITY % SVG.module    "INCLUDE" >

<![%XHTML.module;[
<!ENTITY % XHTML.version
         "-//W3C//DTD XHTML 1.1 plus MathML 2.0 plus SVG 1.1//EN" >
]]>

<!-- Switches to enable subsets.
-->
<!ENTITY % XHTML.Basic.module "IGNORE" >
<!ENTITY % SVG.Basic.module   "IGNORE" >
<!ENTITY % SVG.Tiny.module    "IGNORE" >

<!-- Use the following entities to identify the namespaces:
-->
<!ENTITY % XHTML.xmlns       "http://www.w3.org/1999/xhtml" >
<!ENTITY % MATHML.xmlns      "http://www.w3.org/1998/Math/MathML" >
<!ENTITY % MATHML.pref.xmlns "http://www.w3.org/2002/Math/preference" >
<!ENTITY % SVG.xmlns         "http://www.w3.org/2000/svg" >
<!ENTITY % XLINK.xmlns       "http://www.w3.org/1999/xlink" >

<!-- Declare base URIs for the relevant DTD modules.
-->
<![%XHTML.module;[
<!ENTITY % XHTML.sysid.base
         "http://www.w3.org/TR/xhtml-modularization/DTD/" >
]]>
<![%MATHML.module;[
<!ENTITY % MATHML.sysid.base
         "http://www.w3.org/Math/DTD/mathml2/" >
]]>
<![%SVG.module;[
<!ENTITY % SVG.sysid.base
         "http://www.w3.org/Graphics/SVG/1.1/DTD/" >
]]>

<!-- Declare system identifiers for the relevant DTD modules.
-->
<![%XHTML.module;[
<![%XHTML.Basic.module;[
<!ENTITY % XHTML.dtd.fpi
         "-//W3C//DTD XHTML Basic 1.0//EN" >
<!ENTITY % XHTML.dtd.sysid
         "http://www.w3.org/TR/xhtml-basic/xhtml-basic10.dtd" >
]]>
<!ENTITY % XHTML.dtd.fpi
         "-//W3C//DTD XHTML 1.1//EN" >
<!ENTITY % XHTML.dtd.sysid
         "http://www.w3.org/TR/xhtml11/DTD/xhtml11.dtd" >
]]>
<![%MATHML.module;[
<!ENTITY % MATHML.dtd.sysid
         "%MATHML.sysid.base;mathml2.dtd" >
<!ENTITY % MATHML.qname.sysid
         "%MATHML.sysid.base;mathml2-qname-1.mod" >
]]>
<![%SVG.module;[
<![%SVG.Tiny.module;[
<!ENTITY % SVG.dtd.fpi
         "-//W3C//DTD SVG 1.1 Tiny//EN" >
<!ENTITY % SVG.dtd.sysid
         "%SVG.sysid.base;svg11-tiny.dtd" >
]]>
<![%SVG.Basic.module;[
<!ENTITY % SVG.dtd.fpi
         "-//W3C//DTD SVG 1.1 Basic//EN" >
<!ENTITY % SVG.dtd.sysid
         "%SVG.sysid.base;svg11-basic.dtd" >
]]>
<!ENTITY % SVG.dtd.fpi
         "-//W3C//DTD SVG 1.1//EN" >
<!ENTITY % SVG.dtd.sysid
         "%SVG.sysid.base;svg11.dtd" >
]]>

<!-- See the XHTML / MathML / SVG Qualified Names modules for information
     on the use of namespace prefixes in the DTD.  Default values are
     as follows:

       <!ENTITY % NS.prefixed "IGNORE" >
       <!ENTITY % XHTML.prefixed "%NS.prefixed;" >
       <!ENTITY % XHTML.prefix  "" >
       <!ENTITY % MATHML.prefixed "%NS.prefixed;" >
       <!ENTITY % MATHML.prefix   "m" >
       <!ENTITY % MATHML.pref.prefixed "IGNORE" >
       <!ENTITY % MATHML.pref.prefix "pref" >
       <!ENTITY % SVG.prefixed "%NS.prefixed;" >
       <!ENTITY % SVG.prefix "" >
       <!ENTITY % XLINK.prefix "xlink" >

     In this DTD driver, XHTML and MathML are not prefixed, and SVG is
     prefixed by default.  It can be changed by redeclaring the above
     parameter entities.
-->
<!ENTITY % XHTML.prefixed       "IGNORE" >
<!ENTITY % MATHML.prefixed      "IGNORE" >
<!ENTITY % MATHML.prefix        "m" >
<!ENTITY % MATHML.pref.prefixed "IGNORE" >
<!ENTITY % MATHML.pref.prefix   "pref" >
<!ENTITY % SVG.prefixed         "INCLUDE" >
<!ENTITY % SVG.prefix           "svg" >
<!ENTITY % XLINK.prefix         "xlink" >

<!-- a URI reference, see [URI] -->
<!ENTITY % URI.datatype "CDATA" >

<!-- Declare a parameter entity %XLINK.xmlns.attrib; containing
     the XML Namespace declarations for XLink.
-->
<!ENTITY % XLINK.xmlns.attrib
    "xmlns:%XLINK.prefix; %URI.datatype; #FIXED '%XLINK.xmlns;'"
>

<!-- Allow universal MathML stylesheet-related declarations.
     When it is used, it must always be prefixed.
-->
<![%MATHML.module;[
<![%MATHML.pref.prefixed;[
<!ENTITY % MATHML.pref.renderer.extra "">
<!ENTITY % MATHML.pref.renderer
    "css | mathplayer-dl | mathplayer | techexplorer-plugin | techexplorer">
<!ENTITY % MATHML.pref.xmlns.attrib
    "xmlns:%MATHML.pref.prefix; %URI.datatype; #FIXED '%MATHML.pref.xmlns;'
     %MATHML.pref.prefix;:renderer
     ( %MATHML.pref.renderer; %MATHML.pref.renderer.extra; ) #IMPLIED"
>
]]>
]]>
<!ENTITY % MATHML.pref.xmlns.attrib "" >

<!-- The parameter entities %SVG.xmlns.extra.attrib; and
     %XHTML.xmlns.extra.attrib; may be redeclared to contain
     any foreign namespace declarations for namespaces embedded
     in XHTML+MathML+SVG. The default value is an empty string.
-->
<!ENTITY % SVG.xmlns.extra.attrib "" >
<!ENTITY % XHTML.xmlns.extra.attrib "" >

<!-- Declare parameter entities to define XML Namespace declarations
     for SVG, XHTML and MathML.
-->
<![%SVG.module;[
<![%SVG.prefixed;[
<!ENTITY % SVG.xmlns.decl.attrib
    "xmlns:%SVG.prefix; %URI.datatype; #FIXED '%SVG.xmlns;'"
>
]]>
<!ENTITY % SVG.xmlns.decl.attrib
    "xmlns %URI.datatype; #FIXED '%SVG.xmlns;'"
>
]]>
<!ENTITY % SVG.xmlns.decl.attrib "" >

<![%XHTML.module;[
<![%XHTML.prefixed;[
<!ENTITY % XHTML.xmlns.decl.attrib
    "xmlns:%XHTML.prefix; %URI.datatype; #FIXED '%XHTML.xmlns;'"
>
]]>
<!ENTITY % XHTML.xmlns.decl.attrib
    "xmlns %URI.datatype; #FIXED '%XHTML.xmlns;'"
>
]]>
<!ENTITY % XHTML.xmlns.decl.attrib "" >

<![%MATHML.module;[
<![%MATHML.prefixed;[
<!ENTITY % MATHML.xmlns.decl.attrib
    "xmlns:%MATHML.prefix; %URI.datatype; #FIXED '%MATHML.xmlns;'"
>
]]>
<!ENTITY % MATHML.xmlns.decl.attrib
    "xmlns %URI.datatype; #FIXED '%MATHML.xmlns;'"
>
]]>
<!ENTITY % MATHML.xmlns.decl.attrib "" >

<!-- Declare common case for %NS.decl.attrib;.
-->
<!ENTITY % NS.common.decl.attrib
    "%SVG.xmlns.decl.attrib;
     %XHTML.xmlns.decl.attrib;
     %MATHML.xmlns.decl.attrib;
     %XLINK.xmlns.attrib;
     %MATHML.pref.xmlns.attrib;
     %SVG.xmlns.extra.attrib;
     %XHTML.xmlns.extra.attrib;"
>

<!-- Redeclare the parameter entity %NS.decl.attrib; containing
     all XML Namespace declarations used in the DTD, its form
     dependent on whether prefixing is active.
-->
<![%SVG.prefixed;[
<![%XHTML.prefixed;[
<!-- SVG and XHTML are prefixed, MathML is either prefixed or not prefixed.
-->
<!ENTITY % NS.decl.attrib
    "%NS.common.decl.attrib;"
>
]]>
<![%MATHML.prefixed;[
<!-- SVG and MathML are prefixed, XHTML is not prefixed.
-->
<!ENTITY % NS.decl.attrib
    "%NS.common.decl.attrib;"
>
]]>
<!-- SVG is prefixed, XHTML and MathML are not prefixed.
     MathML namespace must always be specified on the math element.
-->
<!ENTITY % NS.decl.attrib
    "%SVG.xmlns.decl.attrib;
     %XHTML.xmlns.decl.attrib;
     %XLINK.xmlns.attrib;
     %MATHML.pref.xmlns.attrib;
     %SVG.xmlns.extra.attrib;
     %XHTML.xmlns.extra.attrib;"
>
]]>
<![%XHTML.prefixed;[
<![%MATHML.prefixed;[
<!-- SVG is not prefixed, XHTML and MathML are prefixed.
-->
<!ENTITY % NS.decl.attrib
    "%NS.common.decl.attrib;"
>
]]>
<!-- SVG and MathML are not prefixed, which is not allowed.
-->
<!ENTITY % NS.decl.attrib "" >
]]>
<!-- SVG, MathML and XHTML are all not prefixed, which is not allowed.
-->
<!ENTITY % NS.decl.attrib "" >

<!-- Redeclare parameter entities %SVG.xmlns.attrib; and
     %XHTML.xmlns.attrib; containing all XML namespace declarations
     used by XHTML+MathML+SVG, including a default xmlns declaration
     when prefixing is inactive.
-->
<![%SVG.module;[
<!ENTITY % SVG.xmlns.attrib
    "%NS.decl.attrib;"
>
]]>

<![%XHTML.module;[
<!ENTITY % XHTML.xmlns.attrib
    "%NS.decl.attrib;"
>
]]>

<!-- Redeclare the parameter entity %MATHML.xmlns.extra.attrib;
     containing XLink and MathML preferences namespace declarations
     allowed on MathML elements.
-->
<![%MATHML.module;[
<!ENTITY % MATHML.xmlns.extra.attrib
    "%XLINK.xmlns.attrib;
     %MATHML.pref.xmlns.attrib;"
>
]]>

<!-- Framework Redeclaration placeholders  ....................... -->

<![%XHTML.module;[
<!ENTITY % XHTML.redecl.module "INCLUDE" >
<![%XHTML.redecl.module;[
<!-- Pre-Framework Redeclaration placeholder  .................... -->
<!ENTITY % xhtml-prefw-redecl.mod "" >

<!-- Post-Framework Redeclaration placeholder  ................... -->
<!ENTITY % xhtml-postfw-redecl.mod "" >
]]>
]]>

<![%SVG.module;[
<!ENTITY % SVG.redecl.module "INCLUDE" >
<![%SVG.redecl.module;[
<!-- Pre-Framework Redeclaration placeholder ..................... -->
<!ENTITY % svg-prefw-redecl.mod "" >

<!-- Post-Framework Redeclaration placeholder .................... -->
<!ENTITY % svg-postfw-redecl.mod "" >
]]>
]]>

<!-- ::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::: -->

<!-- Declare MathML Qualified Names module as an extension of
     XHTML's Qualified Names module.
-->
<![%MATHML.module;[
<!ENTITY % xhtml-qname-extra.decl
    'PUBLIC "-//W3C//ENTITIES MathML 2.0 Qualified Names 1.0//EN"
            "%MATHML.qname.sysid;"'
>
<!ENTITY % xhtml-qname-extra.mod
    %xhtml-qname-extra.decl;
>
]]>

<!-- Declare location of math and svg contents in XHTML.
-->

<![%MATHML.module;[
<![%MATHML.prefixed;[
<!ENTITY % MATHML.pfx        "%MATHML.prefix;:" >
]]>
<!ENTITY % MATHML.pfx        "" >
<!ENTITY % math.qname        "%MATHML.pfx;math" >
<!ENTITY % MATHML.math.class "| %math.qname;" >
]]>
<!ENTITY % MATHML.math.class "" >

<![%SVG.module;[
<![%SVG.prefixed;[
<!ENTITY % SVG.pfx           "%SVG.prefix;:" >
]]>
<!ENTITY % SVG.pfx           "" >
<!ENTITY % SVG.svg.qname     "%SVG.pfx;svg" >
<!ENTITY % SVG.svg.class     "| %SVG.svg.qname;" >
]]>
<!ENTITY % SVG.svg.class     "" >

<![%XHTML.module;[
<![%XHTML.Basic.module;[
<!ENTITY % Misc.class
    "%MATHML.math.class; %SVG.svg.class;" >
]]>
<!ENTITY % Misc.extra
    "%MATHML.math.class; %SVG.svg.class;" >
]]>

<!-- Redeclare SVG's foreignObject content (allow anything).
-->
<![%SVG.module;[
<!ENTITY % SVG.foreignObject.content "ANY" >
]]>

<!-- ::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::: -->

<!-- Instantiate SVG DTD  ........................................ -->
<![%SVG.module;[
<!ENTITY % SVG.dtd.decl
    'PUBLIC "%SVG.dtd.fpi;"
            "%SVG.dtd.sysid;"'
>
<!ENTITY % SVG.dtd %SVG.dtd.decl; >
%SVG.dtd;
]]>

<!-- Instantiate XHTML DTD  ...................................... -->
<![%XHTML.module;[
<!ENTITY % XHTML.dtd.decl
    'PUBLIC "%XHTML.dtd.fpi;"
            "%XHTML.dtd.sysid;"'
>
<!ENTITY % XHTML.dtd %XHTML.dtd.decl; >
%XHTML.dtd;
]]>

<!-- instantiate MathML 2.0 DTD  ................................. -->
<![%MATHML.module;[
<!ENTITY % MATHML.dtd.decl
    'PUBLIC "-//W3C//DTD MathML 2.0//EN"
            "%MATHML.dtd.sysid;"'
>
<!ENTITY % MATHML.dtd %MATHML.dtd.decl; >
%MATHML.dtd;
]]>

<!-- end of xhtml-math-svg.dtd -->

3.  How to use XHTML 1.1 + MathML 2.0 + SVG 1.1 DTD

This section is informative.

As shown in the above DTD driver, a couple of parameter entities are prepared to switch on/off namespace prefixes and to change namespace prefixes arbitrarily. The default values are as follows:

<!ENTITY % XHTML.prefixed  "IGNORE" >
<!ENTITY % XHTML.prefix    "" >
<!ENTITY % MATHML.prefixed "IGNORE" >
<!ENTITY % MATHML.prefix   "m" >
<!ENTITY % SVG.prefixed    "INCLUDE" >
<!ENTITY % SVG.prefix      "svg" >
<!ENTITY % XLINK.prefix    "xlink" >

%XHTML.prefixed;, %MATHML.prefixed;, %SVG.prefixed;

These parameter entities switch on/off namespace prefixing. Setting the value to 'INCLUDE' makes namespace prefixing on, and 'IGNORE' switches off namespace prefixing. By default, XHTML and MathML are not prefixed, and SVG is prefixed with 'svg:'.

Also check the limitation on name collisions.

%XHTML.prefix;, %MATHML.prefix;, %SVG.prefix;, %XLINK.prefix;

These parameter entities set namespace prefixes for relevant vocabularies. These values take effect only if relevant prefixing is enabled. The same prefix may not be used for different vocabularies. Note that XLink attributes must always be prefixed, so the value of %XLINK.prefix; must not be an empty string.

There are also parameter entities that define system identifiers for relevant DTD modules as follows:

<!ENTITY % XHTML.sysid.base
         "http://www.w3.org/TR/xhtml-modularization/DTD/" >
<!ENTITY % MATHML.sysid.base
         "http://www.w3.org/Math/DTD/mathml2/" >
<!ENTITY % SVG.sysid.base
         "http://www.w3.org/Graphics/SVG/1.1/DTD/" >

<!ENTITY % XHTML.dtd.sysid
         "http://www.w3.org/TR/xhtml11/DTD/xhtml11.dtd" >
<!ENTITY % MATHML.dtd.sysid
         "%MATHML.sysid.base;mathml2.dtd" >
<!ENTITY % MATHML.qname.sysid
         "%MATHML.sysid.base;mathml2-qname-1.mod" >
<!ENTITY % SVG.dtd.sysid
         "%SVG.sysid.base;svg11.dtd" >

When necessary, these parameter entities may be overridden to point to local copies of those DTD modules, e.g. for off-line authoring. Authors should not override these parameter entities when delivering the content.

3.1.  XHTML as the Host Language

If authors want to use XHTML as the host language, this DTD driver may be typically invoked as follows:

<!DOCTYPE html PUBLIC
    "-//W3C//DTD XHTML 1.1 plus MathML 2.0 plus SVG 1.1//EN"
    "http://www.w3.org/2002/04/xhtml-math-svg/xhtml-math-svg.dtd">

If necessary, authors may change the above parameter entities as appropriate in the internal DTD subset. A typical document might look something like this:

<?xml version="1.0"?>
<!DOCTYPE html PUBLIC
    "-//W3C//DTD XHTML 1.1 plus MathML 2.0 plus SVG 1.1//EN"
    "http://www.w3.org/2002/04/xhtml-math-svg/xhtml-math-svg.dtd">
<html xmlns="http://www.w3.org/1999/xhtml" xml:lang="en">
  <head>
    <title>XHTML as the host language</title>
  </head>
  <body>
    ... XHTML content ...
    <math xmlns="http://www.w3.org/1998/Math/MathML">
      ... MathML content ...
    </math>
    ... XHTML content ...
    <svg:svg version="1.1"
      xmlns:svg="http://www.w3.org/2000/svg"
      xmlns:xlink="http://www.w3.org/1999/xlink">
      ... SVG content ...
      <svg:switch>
        <svg:foreignObject ...>
          <p>
            ... XHTML content ...
            <math xmlns="http://www.w3.org/1998/Math/MathML">
              ... MathML content ...
            </math>
            ... XHTML content ...
          </p>
        </svg:foreignObject>
      </svg:switch>
    </svg:svg>
  </body>
</html>

If MathML is not prefixed, the MathML namespace must always be declared on the math element to avoid confusion of namespace defaulting with XHTML.

3.2.  SVG as the Host Language

If authors want to use SVG as the host language, this DTD driver may be typically invoked as follows:

<!DOCTYPE svg:svg PUBLIC
    "-//W3C//DTD XHTML 1.1 plus MathML 2.0 plus SVG 1.1//EN"
    "http://www.w3.org/2002/04/xhtml-math-svg/xhtml-math-svg.dtd">

In this case SVG elements are still prefixed and XHTML and MathML elements are not prefixed. In order to make SVG elements non-prefixed, authors may adjust relevant parameter entities in the internal DTD subset like this:

<?xml version="1.0"?>
<!DOCTYPE svg PUBLIC
    "-//W3C//DTD XHTML 1.1 plus MathML 2.0 plus SVG 1.1//EN"
    "http://www.w3.org/2002/04/xhtml-math-svg/xhtml-math-svg.dtd"[
<!ENTITY % SVG.prefixed "IGNORE" >
<!ENTITY % XHTML.prefixed "INCLUDE" >
<!ENTITY % XHTML.prefix "xhtml" >
<!ENTITY % MATHML.prefixed "INCLUDE" >
<!ENTITY % MATHML.prefix "math" >
]>
<svg version="1.1" xml:lang="en"
     xmlns="http://www.w3.org/2000/svg"
     xmlns:xlink="http://www.w3.org/1999/xlink">
  <desc>SVG as the host language</desc>
  ... SVG content ...
  <switch>
    <foreignObject ...>
      <xhtml:p xmlns:xhtml="http://www.w3.org/1999/xhtml">
        ... XHTML content ...
        <math:math xmlns:math="http://www.w3.org/1998/Math/MathML">
          ... MathML content ...
        </math:math>
        ... XHTML content ...
      </xhtml:p>
    </foreignObject>
  </switch>
  ... SVG content ...
</svg>

Note that the namespace declarations may be collectively declared on the root element (or other elements), like:

<?xml version="1.0"?>
<!DOCTYPE svg PUBLIC
    "-//W3C//DTD XHTML 1.1 plus MathML 2.0 plus SVG 1.1//EN"
    "http://www.w3.org/2002/04/xhtml-math-svg/xhtml-math-svg.dtd"[
<!ENTITY % SVG.prefixed "IGNORE" >
<!ENTITY % XHTML.prefixed "INCLUDE" >
<!ENTITY % XHTML.prefix "xhtml" >
<!ENTITY % MATHML.prefixed "INCLUDE" >
<!ENTITY % MATHML.prefix "math" >
]>
<svg version="1.1" xml:lang="en"
     xmlns="http://www.w3.org/2000/svg"
     xmlns:xlink="http://www.w3.org/1999/xlink"
     xmlns:xhtml="http://www.w3.org/1999/xhtml"
     xmlns:math="http://www.w3.org/1998/Math/MathML">
  <desc>SVG as the host language</desc>
  ... SVG content ...
  <switch>
    <foreignObject ...>
      <xhtml:p>
        ... XHTML content ...
        <math:math>
          ... MathML content ...
        </math:math>
        ... XHTML content ...
      </xhtml:p> 
   </foreignObject>
  </switch>
  ... SVG content ...
</svg>

3.3.  Using MathML with Universal MathML stylesheet

When using MathML, authors may wish to use the "Universal MathML stylesheet" [MathML-XSL] to make it possible to be viewed on a large number of Web browsers. This DTD driver allows authors to use this XSLT stylesheet easily. The DTD driver includes the following parameter entities:

<!ENTITY % MATHML.pref.prefixed "IGNORE" >
<!ENTITY % MATHML.pref.prefix   "pref" >

Authors may include an XML stylesheet processing instruction for the universal MathML stylesheet as explained in "Putting mathematics on the Web with MathML" [MathML-XSL], and when they want to specify preferences for the MathML renderer, they may set the %MATHML.pref.prefixed; parameter entity to "INCLUDE". This allows authors to declare the MathML preferences namespace and use the renderer attribute like this:

<?xml version="1.0"?>
<?xml-stylesheet type="text/xsl" href="http://www.w3.org/Math/XSL/mathml.xsl"?>
<!DOCTYPE html PUBLIC
    "-//W3C//DTD XHTML 1.1 plus MathML 2.0 plus SVG 1.1//EN"
    "http://www.w3.org/2002/04/xhtml-math-svg/xhtml-math-svg.dtd"[
<!ENTITY % MATHML.pref.prefixed "INCLUDE" >
]>
<html xmlns="http://www.w3.org/1999/xhtml" xml:lang="en"
      xmlns:pref="http://www.w3.org/2002/Math/preference"
      pref:renderer="css">
  <head> ... </head>
  <body> ... </body>
</html>

The namespace prefix for the MathML preferences namespace may be changed by redeclaring the %MATHML.pref.prefix; parameter entity in the internal DTD subset.

4.  How to define new profiles from XHTML 1.1 + MathML 2.0 + SVG 1.1 DTD

This section is informative.

This DTD driver can also be used as a basis for defining other profiles that combine some or all of XHTML, MathML and SVG. This DTD driver has switches to include/ignore each vocabulary, all set to "INCLUDE" by default:

<!ENTITY % XHTML.module  "INCLUDE" >
<!ENTITY % MATHML.module "INCLUDE" >
<!ENTITY % SVG.module    "INCLUDE" >

For example, by redeclaring the %MATHML.module; parameter entity to "IGNORE", this DTD driver can be used as an XHTML 1.1 + SVG 1.1 DTD.

People might want to use other XHTML Family document type such as XHTML Basic [XHTMLBasic] instead of XHTML 1.1, or other SVG profiles like SVG Basic/Tiny [SVGMobile] instead of full SVG 1.1. There are predefined parameter entities to allow those subsets easily, all set to "IGNORE" by default:

<!ENTITY % XHTML.Basic.module "IGNORE" >
<!ENTITY % SVG.Basic.module   "IGNORE" >
<!ENTITY % SVG.Tiny.module    "IGNORE" >

By redeclaring the %XHTML.Basic.module; parameter entity to "INCLUDE", this DTD driver will use XHTML Basic instead of XHTML 1.1 for XHTML part. Likewise, %SVG.Basic.module; and %SVG.Tiny.module; control whether to use SVG Basic/Tiny instead of SVG 1.1, respectively. When both %SVG.Basic.module; and %SVG.Tiny.module; are set to "INCLUDE", SVG Tiny will be used.

Using this mechanism, XHTML Basic + SVG Tiny DTD can be simply written like this:

<!-- ....................................................................... -->
<!-- XHTML Basic plus SVG Tiny DTD  ........................................ -->
<!-- URI: http://www.w3.org/2002/04/xhtml-math-svg/xhtml-basic-svg-tiny.dtd
-->

<!ENTITY % XHTML.version
         "-//W3C//DTD XHTML Basic plus SVG Tiny//EN" >

<!ENTITY % XHTML.Basic.module "INCLUDE" >
<!ENTITY % MATHML.module      "IGNORE" >
<!ENTITY % SVG.Tiny.module    "INCLUDE" >

<!ENTITY % XHTML-MATH-SVG.dtd
    PUBLIC "-//W3C//DTD XHTML 1.1 plus MathML 2.0 plus SVG 1.1//EN" 
           "http://www.w3.org/2002/04/xhtml-math-svg/xhtml-math-svg.dtd" >
%XHTML-MATH-SVG.dtd;

<!-- end of xhtml-basic-svg-tiny.dtd -->

In addition, each DTD is parameterized as %XHTML.dtd;, %MATHML.dtd; and %SVG.dtd;, so by redeclaring the relevant parameter entity to refer to a different DTD, different profile may be easily defined.

5.  Known limitations

This section is informative.

Although this DTD driver has taken a great stride to provide as much flexibility as possible, there are some limitations, mostly due to the limitation of the DTD mechanism itself.

• Due to name collisions, XHTML and SVG, or MathML and SVG cannot be used together without prefixing either of them.
• Arbitrary prefixes can be chosen, but those cannot be changed in the middle of the same document (e.g. if authors choose to prefix SVG elements, authors have to always prefix them and have to use the same prefix throughout the document, and they cannot use defaulting in that document).
• Only MathML and XLink namespace declarations are allowed on MathML elements, and XHTML or SVG namespaces cannot be declared.
• This DTD driver is not designed to allow arbitrary foreign namespaces (simply not possible with DTD). Adding yet another vocabulary beyond XHTML+MathML+SVG may not be trivial, either.

• ISSUE: At the moment, inside SVG, XHTML and MathML fragments are only allowed through the foreignObject element. It would make sense to also allow those foreign namespace fragments inside the desc and title elements. Future update of this profile may allow such integration.

  It is also under discussion whether to allow those foreign namespace fragments directly inside elements like text and tspan. Such a close integration would be useful for mathematical diagrams, but the processing needs to be clarified.

Informative references

[MathML-XSL]

"Putting mathematics on the Web with MathML", W3C Math Working Group, 2002.

[SVGMobile]

"Mobile SVG Profiles: SVG Tiny and SVG Basic", W3C Candidate Recommendation

T. Capin, ed., 30 April 2002, work in progress.

Available at: http://www.w3.org/TR/2002/CR-SVGMobile-20020430/

The latest version is available at: http://www.w3.org/TR/SVGMobile/

[XHTMLBasic]

"XHTML™ Basic", W3C Recommendation

M. Baker, M. Ishikawa, S. Matsui, P. Stark, T. Wugofski, T. Yamakami, eds., 19 December 2000. Available at: http://www.w3.org/TR/2000/REC-xhtml-basic-20001219

The latest version is available at: http://www.w3.org/TR/xhtml-basic

[XHTMLMODSchema]

"Modularization of XHTML™ in XML Schema", W3C Working Draft

D. Austin, S. P. McCarron, eds., 19 December 2001, work in progress.

Available at: http://www.w3.org/TR/2001/WD-xhtml-m12n-schema-20011219

The latest version is available at: http://www.w3.org/TR/xhtml-m12n-schema

[XMLSchema]

"XML Schema Part 1: Structures", W3C Recommendation

H. S. Thompson, D. Beech, M. Maloney, N. Mendelsohn, eds., 2 May 2001.

Available at: http://www.w3.org/TR/2001/REC-xmlschema-1-20010502

The latest version is available at: http://www.w3.org/TR/xmlschema-1

See also "XML Schema Part 2: Datatypes", available at: http://www.w3.org/TR/2001/REC-xmlschema-2-20010502

The latest version is available at: http://www.w3.org/TR/xmlschema-2

Changes from previous Working Draft

This section is informative.

2.1.  XHTML 1.1 + MathML 2.0 + SVG 1.1 DTD Driver

Added mechanism to allow subsets easily.

Changed %MATHML.sysid.base; to point to an updated MathML 2.0 DTD.

3.1.  XHTML as the Host Language

Fixed wrong namespace declaration for SVG in the example.

4.  How to define new profiles from XHTML 1.1 + MathML 2.0 + SVG 1.1 DTD

Added explanation for new subset mechanism, and updated XHTML Basic + SVG Tiny DTD example to use this mechanism.

5.  Known limitations

With the update of MathML 2.0 DTD, the limitation about XLink namespace declarations on MathML elements has been removed.

Added an issue about more close integration of XHTML/MathML inside SVG

Acknowledgments

This section is informative.

(To be added)