stmml.xsd

<?xml version="1.0" encoding="UTF-8"?>
<xsd:schema xmlns:xsd="http://www.w3.org/2001/XMLSchema" 
  xmlns="http://www.xml-cml.org/schema/stmml-1.1"   
  xmlns:sch="http://www.ascc.net/xml/schematron"  
  targetNamespace="http://www.xml-cml.org/schema/stmml-1.1" 
  elementFormDefault="qualified">
  <xsd:annotation>
    <xsd:documentation xml:lang="en">
      <div class="curation">
        <ul>
          <li>created by hand
      2001-11-20</li>
          <li>First draft 2001-11-20</li>
        </ul>
        <p>STMML supports domain-independent STM information components</p>
      </div>
    </xsd:documentation>
  </xsd:annotation>
  <xsd:annotation>
    <xsd:appinfo>
      <sch:title>Schematron validation</sch:title>
      <sch:ns uri="http://www.xml-cml.org/schema/stmml-1.1"/>
    </xsd:appinfo>
  </xsd:annotation>
  <xsd:annotation>
    <xsd:documentation>
      <div class="heading">Data Types and Data Structure</div>
    </xsd:documentation>
  </xsd:annotation>
  <xsd:annotation>
    <xsd:documentation>
      <div class="subheading">Overview</div>
      <div class="description">
        <p>STM-ML defines a number of data types suited to STM. It also defines
    a number of complex data strucures such as arrays, matrices and tables.
    the constraints are sometimes created through elements and sometimes
    through attributes. We classify the general components as follows:</p>
        <p>
          <b>Abstract Data Structures</b>
        </p>
        <ul>
          <li>
            <a href="el.scalar">scalar</a>. A scalar quantity, expressible as a string, but
    with many optional facets such as errors, units, ranges, etc. Most elements
    may have <a href="st.countType">countType</a> attribute to indicate more than
    one instance.</li>
          <li>
            <a href="el.array">array</a>. An array of homogeneous <tt>scalar</tt>s
    whose size is described by <a href="st.sizeType">sizeType</a>. <a href="st.delimiterType">
    Delimiter</a>s in string representations can ve varied.</li>
          <li>
            <a href="el.matrix">matrix</a>. A rectangular (often square) matrix of
    homogeneous <tt>scalar</tt>s. Many matrices have special functions
    (see <a href="el.matrixType">matrixType</a>) such as geometric
    transformations</li>
          <li>
            <a href="el.table">table</a>. An table where the columns are homogeneous
    <tt>array</tt>s. </li>
          <li>
            <a href="el.list">list</a>. A list of heterogeneous components from any
    namespace.</li>
          <li>
            <a href="st.sizeType">sizeType</a>. Size of arrays</li>
          <li>
            <a href="st.delimiterType">delimiterType</a>. A lexical delimiter</li>
        </ul>
        <p>
          <b>Links and References</b>
        </p>
        <ul>
          <li>
            <a href="el.link">link</a>. Support for simple hyperlinks and link structures</li>
          <li>
            <a href="st.refType">refType</a>. A reference to an element</li>
          <li>
            <a href="st.namespaceRefType">namespaceRefType</a>. A reference to an element, including
    namespace-like prefixes</li>
        </ul>
        <p>
          <b>Data-based simpleTypes</b>
        </p>
        <ul>
          <li>
            <a href="st.coordinate2Type">coordinate2Type</a>. A 2-D coordinate</li>
          <li>
            <a href="st.coordinate3Type">coordinate3Type</a>. A 3-D coordinate</li>
          <li>
            <a href="st.dataTypeType">dataTypeType</a>. An enumeration of
    data types (similar to those in XML Schema).</li>
          <li>
            <a href="st.errorBasisType">errorBasisType</a>. Basis of numeric error estimates</li>
          <li>
            <a href="st.minType">minType</a>. Minimum value</li>
          <li>
            <a href="st.maxType">maxType</a>. Maximum value</li>
        </ul>
        <p>
          <b>Common attribute types</b>
        </p>
        <ul>
          <li>
            <a href="st.idType">idType</a>. Specifies lexical patterns for IDs</li>
          <li>
            <a href="attGp.idGroup">idGroup</a>. ID attribute (highly encouraged)</li>
          <li>
            <a href="attGp.titleGroup">titleGroup</a>. Title attribute (highly encouraged)</li>
          <li>
            <a href="attGp.convGroup">convGroup</a>. Convention attribute</li>
        </ul>
      </div>
    </xsd:documentation>
  </xsd:annotation>
  <xsd:annotation>
    <xsd:documentation>
      <div class="subheading">Data structure</div>
    </xsd:documentation>
  </xsd:annotation>
  <xsd:element name="array" id="el.array">
    <xsd:annotation>
      <xsd:documentation>
        <div class="summary">
            A homogenous 1-dimensional array of similar objects.</div>
        <div class="description">
          <p>
            <tt>array</tt> manages a homogenous 1-dimensional array of similar objects. These
            can be encoded as strings (i.e. XSD-like datatypes) and are concatenated as
            string content. The size of the array should always be &gt;= 1.
         </p>
          <p>The default delimiter is whitespace. The <tt>normalize-space()</tt> function of
         XSLT could be used to normalize all whitespace to single spaces and this would not affect
         the value of the array elements. To extract the elements <tt>java.lang.StringTokenizer</tt>
         could be used. If the elements themselves contain whitespace then a different delimiter
         must be used and is identified through the <tt>delimiter</tt> attribute. This method is
         mandatory if it is required to represent empty strings. If a delimiter is used it MUST
         start and end the array - leading and trailing whitespace is ignored. Thus <tt>size+1</tt>
         occurrences of the delimiter character are required. If non-normalized whitespace is to be
         encoded (e.g. newlines, tabs, etc) you are recommended to translate it character-wise
         to XML character entities.
         </p>
          <p>Note that normal Schema validation tools cannot validate the elements
         of <b>array</b> (they are defined as <tt>string</tt>) However if the string is
         split, a temporary schema
         can be constructed from the type and used for validation. Also the type
         can be contained in a dictionary and software could decide to retrieve this
         and use it for validation.</p>
          <p>When the elements of the <tt>array</tt> are not simple scalars
         (e.g. <a href="el.scalar">scalar</a>s with a value and an error, the
         <tt>scalar</tt>s should be used as the elements. Although this is
         verbose, it is simple to understand. If there is a demand for
         more compact representations, it will be possible to define the
         syntax in a later version.</p>
        </div>
        <div class="example">
          <pre>
&lt;array size="5" title="value"
  dataType="xsd:decimal"&gt;  1.23 2.34 3.45 4.56 5.67&lt;/array&gt;

</pre>
          <p>the <tt>size</tt> attribute is not mandatory but provides a useful validity
         check): </p>
        </div>
        <div class="example">
          <pre>
&lt;array size="5" title="initials" dataType="xsd:string"
  delimiter="/"&gt;/A B//C/D-E/F/&lt;/array&gt;

</pre>
          <p>Note that the second array-element is the empty string ''.</p>
        </div>
        <div class="example">
          <pre>
&lt;array title="mass" size="4"
  units="unit:g"
  errorBasis="observedStandardDeviation"
  minValues="10 11 10 9"
  maxValues="12 14 12 11"
  errorValues="1 2 1 1"
  dataType="xsd:float"&gt;11 12.5 10.9 10.2
&lt;/array&gt;

</pre>
        </div>
      </xsd:documentation>
      <xsd:appinfo>
        <sch:pattern xmlns="http://www.ascc.net/xml/schematron" name="array">
         </sch:pattern>
      </xsd:appinfo>
    </xsd:annotation>
    <xsd:complexType>
      <xsd:simpleContent>
        <xsd:extension base="xsd:string">
          <xsd:attributeGroup ref="tit_id_conv_dictGroup"/>
          <xsd:attribute name="dataType" type="dataTypeType" default="xsd:string">
            <xsd:annotation>
              <xsd:documentation>
                <div class="summary">all elements of the array must have the same dataType</div>
              </xsd:documentation>
            </xsd:annotation>
          </xsd:attribute>
          <xsd:attribute name="errorValues" type="floatArrayType">
            <xsd:annotation>
              <xsd:documentation>
                <div class="summary">an optional array of error values for numeric arrays</div>
              </xsd:documentation>
            </xsd:annotation>
          </xsd:attribute>
          <xsd:attribute name="errorBasis" type="errorBasisType">
            <xsd:annotation>
              <xsd:documentation>
                <div class="summary">A string describing the basis of the errors</div>
              </xsd:documentation>
            </xsd:annotation>
          </xsd:attribute>
          <xsd:attribute name="minValues" type="floatArrayType">
            <xsd:annotation>
              <xsd:documentation>
                <div class="summary">an optional array of minimum values for numeric arrays</div>
              </xsd:documentation>
            </xsd:annotation>
          </xsd:attribute>
          <xsd:attribute name="maxValues" type="floatArrayType">
            <xsd:annotation>
              <xsd:documentation>
                <div class="summary">an optional array of maximum values for numeric arrays</div>
              </xsd:documentation>
            </xsd:annotation>
          </xsd:attribute>
          <xsd:attribute name="units" type="unitsType">
            <xsd:annotation>
              <xsd:documentation>
                <div class="summary">a string denoting the units (recommended for numeric quantities!!).
                   All elements must have the same units</div>
              </xsd:documentation>
            </xsd:annotation>
          </xsd:attribute>
          <xsd:attribute name="delimiter" type="delimiterType"/>
          <xsd:attribute name="size" type="xsd:positiveInteger"/>
        </xsd:extension>
      </xsd:simpleContent>
    </xsd:complexType>
  </xsd:element>
  <xsd:element name="scalar" id="el.scalar">
    <xsd:annotation>
      <xsd:documentation>
        <div class="summary">An element to hold scalar data.</div>
        <div class="description">
          <p>
            <tt>scalar</tt> holds scalar data under a single
            generic container. The semantics are usually resolved by
            linking to a dictionary.
             <b>scalar</b> defaults to a scalar string but
             has attributes which affect the type.
         </p>
          <p>
            <tt>scalar</tt> does not necessarily reflect a physical object (for which
         <a href="el.object">object</a> should be used). It may reflect a property of an object
         such as temperature, size, etc. </p>
          <p>Note that normal Schema validation tools cannot validate the data type
         of <b>scalar</b> (it is defined as <tt>string</tt>), but that a temporary schema
         can be constructed from the type and used for validation. Also the type
         can be contained in a dictionary and software could decide to retrieve this
         and use it for validation.</p>
        </div>
        <div class="example">
          <pre>
&lt;scalar
    dataType="xsd:decimal"
    errorValue="1.0"
    errorBasis="observedStandardDeviation"
    title="body weight"
    dictRef="zoo:bodywt"
    units="units:g"&gt;34.3&lt;/scalar&gt;

        </pre>
        </div>
      </xsd:documentation>
    </xsd:annotation>
    <xsd:complexType>
      <xsd:simpleContent>
        <xsd:extension base="xsd:string">
          <xsd:attributeGroup ref="tit_id_conv_dictGroup"/>
          <xsd:attribute name="dataType" type="dataTypeType" default="xsd:string"/>
          <xsd:attribute name="errorValue" type="xsd:decimal"/>
          <xsd:attribute name="errorBasis" type="errorBasisType"/>
          <xsd:attribute name="minValue" type="minType"/>
          <xsd:attribute name="maxValue" type="maxType"/>
          <xsd:attribute name="units" type="unitsType"/>
        </xsd:extension>
      </xsd:simpleContent>
    </xsd:complexType>
  </xsd:element>
  <xsd:element name="matrix" id="el.matrix">
    <xsd:annotation>
      <xsd:documentation>
        <div class="summary">A rectangular matrix of any quantities</div>
        <div class="description">
          <p>By default <tt>matrix</tt> represents
        a rectangular matrix of any quantities
            representable as XSD or STMML dataTypes. It consists of
            <tt>rows*columns</tt> elements, where <tt>columns</tt> is the
     fasting moving index. Assuming the elements are counted from 1 they are
     ordered <tt>V[1,1],V[1,2],...V[1,columns],V[2,1],V[2,2],...V[2,columns],
     ...V[rows,1],V[rows,2],...V[rows,columns]</tt>
          </p>
          <p>By default whitespace is used to separate matrix elements; see
     <a href="el.array">array</a> for details. There are NO characters or markup
     delimiting the end of rows; authors must be careful!. The <tt>columns</tt>
     and <tt>rows</tt> attributes have no default values; a row vector requires
     a <tt>rows</tt> attribute of 1.</p>
          <p>
            <tt>matrix</tt> also supports many types of square matrix, but at present we
     require all elements to be given, even if the matrix is symmetric, antisymmetric
     or banded diagonal. The <tt>matrixType</tt> attribute allows software to
     validate and process the type of matrix.</p>
        </div>
        <div class="example">
          <pre>
&lt;matrix id="m1" title="mattrix-1" dictRef="foo:bar"
  rows="3" columns="3" dataType="xsd:decimal"
  delimiter="|" matrixType="squareSymmetric" units="unit:m"
  &gt;|1.1|1.2|1.3|1.2|2.2|2.3|1.3|2.3|3.3!&lt;/matrix&gt;

        </pre>
        </div>
      </xsd:documentation>
    </xsd:annotation>
    <xsd:complexType>
      <xsd:simpleContent>
        <xsd:extension base="xsd:string">
          <xsd:attribute name="dataType" type="dataTypeType" default="xsd:float"/>
          <xsd:attribute name="delimiter" type="delimiterType"/>
          <xsd:attribute name="rows" type="sizeType" use="required">
            <xsd:annotation>
              <xsd:documentation>
                <div class="summary">
                  <p>Number of rows</p>
                </div>
              </xsd:documentation>
            </xsd:annotation>
          </xsd:attribute>
          <xsd:attribute name="columns" type="sizeType" use="required">
            <xsd:annotation>
              <xsd:documentation>
                <div class="summary">
                  <p>Number of columns</p>
                </div>
              </xsd:documentation>
            </xsd:annotation>
          </xsd:attribute>
          <xsd:attribute name="units" type="unitsType">
            <xsd:annotation>
              <xsd:documentation>
                <div class="summary">
                  <p>units (recommended for numeric quantities!!)</p>
                </div>
              </xsd:documentation>
            </xsd:annotation>
          </xsd:attribute>
          <xsd:attributeGroup ref="tit_id_conv_dictGroup"/>
          <xsd:attribute name="matrixType" type="matrixType">
            <xsd:annotation>
              <xsd:documentation>
                <div class="summary">
                  <p>Type of matrix (mainly square ones)</p>
                </div>
              </xsd:documentation>
            </xsd:annotation>
          </xsd:attribute>
          <xsd:attribute name="errorValues" type="floatArrayType">
            <xsd:annotation>
              <xsd:documentation>
                <div class="summary">an optional array of error values for numeric matrices</div>
              </xsd:documentation>
            </xsd:annotation>
          </xsd:attribute>
          <xsd:attribute name="errorBasis" type="errorBasisType">
            <xsd:annotation>
              <xsd:documentation>
                <div class="summary">A string describing the basis of the errors</div>
              </xsd:documentation>
            </xsd:annotation>
          </xsd:attribute>
          <xsd:attribute name="minValues" type="floatArrayType">
            <xsd:annotation>
              <xsd:documentation>
                <div class="summary">an optional array of minimum values for numeric matrices</div>
              </xsd:documentation>
            </xsd:annotation>
          </xsd:attribute>
          <xsd:attribute name="maxValues" type="floatArrayType">
            <xsd:annotation>
              <xsd:documentation>
                <div class="summary">an optional array of maximum values for numeric matrices</div>
              </xsd:documentation>
            </xsd:annotation>
          </xsd:attribute>
        </xsd:extension>
      </xsd:simpleContent>
    </xsd:complexType>
  </xsd:element>
  <xsd:element name="table" id="el.table">
    <xsd:annotation>
      <xsd:documentation>
        <div class="summary">A rectangular table of any quantities</div>
        <div class="description">
          <p>By default <tt>table</tt> represents a rectangular table of any quantities
               representable as XSD or STMML dataTypes. The default layout is columnwise,
               with <tt>columns</tt> columns,
               where each column is a (homogeneous) <a href="el.array">array</a> of
               size <tt>rows</tt> data. This is the "normal" orientation of data tables
               but the table display could be transposed by XSLT transformation if required.
         Access is to columns, and thence to the data within them. DataTyping, delimiters,
         etc are delegated to the arrays, which must all be of the same size. For
         verification it is recommended that every array carries a <tt>size</tt>
         attribute.
               </p>
        </div>
        <div class="example">
          <pre>&lt;table rows="3" columns="2" title="people"&gt;
  &lt;array title="age" dataType="xsd:integer"&gt;3 5 7&lt;/array&gt;
  &lt;array title="name" dataType="xsd:string"&gt;Sue Fred Sandy&lt;/array&gt;
&lt;/table&gt;
</pre>
        </div>
      </xsd:documentation>
    </xsd:annotation>
    <xsd:complexType>
      <xsd:sequence>
        <xsd:element ref="array" maxOccurs="unbounded"/>
      </xsd:sequence>
      <xsd:attribute name="rows" type="sizeType" use="required">
        <xsd:annotation>
          <xsd:documentation>
            <div class="description">
              <p>Number of rows</p>
            </div>
          </xsd:documentation>
        </xsd:annotation>
      </xsd:attribute>
      <xsd:attribute name="columns" type="sizeType" use="required">
        <xsd:annotation>
          <xsd:documentation>
            <div class="description">
              <p>Number of columns</p>
            </div>
          </xsd:documentation>
        </xsd:annotation>
      </xsd:attribute>
      <xsd:attributeGroup ref="tit_id_conv_dictGroup"/>
    </xsd:complexType>
  </xsd:element>
  <xsd:element name="list" id="el.list">
    <xsd:annotation>
      <xsd:documentation>
        <div class="summary">A generic container with no implied semantics</div>
        <div class="description">
          <p>
       A generic container with no implied semantics. It just contains
      things and can have attributes which bind conventions to it. It could often
      act as the root element in an STM document.</p>
        </div>
        <div class="example">
          <pre>
&lt;list&gt;
  &lt;array title="animals"&gt;frog bear toad&lt;/array&gt;
  &lt;scalar title="weight" dataType="xsd:float"&gt;3.456&lt;/scalar&gt;
&lt;/list&gt;

      </pre>
        </div>
      </xsd:documentation>
    </xsd:annotation>
    <xsd:complexType>
      <xsd:sequence>
        <xsd:any minOccurs="0" maxOccurs="unbounded"/>
      </xsd:sequence>
      <xsd:attributeGroup ref="tit_id_conv_dictGroup"/>
      <xsd:attribute name="type" type="xsd:string"/>
    </xsd:complexType>
  </xsd:element>
  <xsd:annotation>
    <xsd:documentation>
      <div class="subheading">Data-based simpleTypes</div>
    </xsd:documentation>
  </xsd:annotation>
  <xsd:simpleType name="coordinate2Type" id="st.coordinate2Type">
    <xsd:annotation>
      <xsd:documentation>
        <div class="summary">An x/y coordinate pair</div>
        <div class="description">
          <p>An x/y coordinate pair consisting of
         two real numbers, separated by whitespace or a comma.
         In arrays and matrices, it may be useful to set a separate delimiter</p>
        </div>
        <div class="example">
          <pre>

&lt;list&gt;
  &lt;array
      &gt;1.2,3.4   3.2,4.5   6.7,23.1 &lt;/array&gt;
  &lt;array delimiter="/"
      &gt;/1.2 3.4/3.2 4.5/6.7 23.1/&lt;/array&gt;
&lt;/list&gt;

        </pre>
        </div>
      </xsd:documentation>
    </xsd:annotation>
    <xsd:restriction base="xsd:string">
      <xsd:pattern value="\s*([\-]|[+])?\d*\.?\d*(\s+|[,])([\-]|[+])?\d*\.?\d*\s*"/>
    </xsd:restriction>
  </xsd:simpleType>
  <xsd:simpleType name="coordinate3Type" id="st.coordinate3Type">
    <xsd:annotation>
      <xsd:documentation>
        <div class="summary">An x/y/z coordinate triple</div>
        <div class="description">
          <p>An x/y/z coordinate triple consisting of
            three real numbers, separated by whitespace or commas.
            In arrays and matrices, it may be useful to set a separate delimiter</p>
        </div>
        <div class="example">
          <pre>
&lt;list&gt;
  &lt;array&gt;1.2,3.4,1.2
    3.2,4.5,7.3   6.7,23.1,5.6 &lt;/array&gt;
  &lt;array delimiter="/"
  &gt;/1.2 3.4 3.3/3.2 4.5 4.5/6.7 23.1 5.6/&lt;/array&gt;
&lt;/list&gt;

           </pre>
        </div>
      </xsd:documentation>
    </xsd:annotation>
    <xsd:restriction base="xsd:string">
      <xsd:pattern value="\s*([\-]|[+])?\d*\.?\d*(\s+|[,])([\-]|[+])?\d*\.?\d*(\s+|[,])([\-]|[+])?\d*\.?\d*\s*"/>
    </xsd:restriction>
  </xsd:simpleType>
  <xsd:simpleType name="dataTypeType" id="st.dataTypeType">
    <xsd:annotation>
      <xsd:documentation>
        <div class="summary">
          <p>an enumerated type for all builtin allowed dataTypes in STM</p>
        </div>
        <div class="description">
          <p>
            <tt>dataTypeType</tt> represents an enumeration of allowed dataTypes
               (at present identical with those in XML-Schemas (Part2- datatypes).
               This means that implementers should be able to use standard XMLSchema-based
               tools for validation without major implementation problems.
            </p>
          <p>It will often be used an an attribute on
            <a href="el.scalar">scalar</a>,
            <a href="el.array">array</a> or
            <a href="el.matrix">matrix</a>
            elements.</p>
        </div>
        <div class="example">
          <pre>
&lt;list xmlns="http://www.xml-cml.org/schema/core"&gt;
  &lt;scalar dataType="xsd:boolean" title="she loves me"&gt;true&lt;/scalar&gt;
  &lt;scalar dataType="xsd:float" title="x"&gt;23.2&lt;/scalar&gt;
  &lt;scalar dataType="xsd:duration" title="egg timer"&gt;PM4&lt;/scalar&gt;
  &lt;scalar dataType="xsd:dateTime" title="current data and time"&gt;2001-02-01:00:30&lt;/scalar&gt;
  &lt;scalar dataType="xsd:time" title="wake up"&gt;06:00&lt;/scalar&gt;
  &lt;scalar dataType="xsd:date" title="where is it"&gt;1752-09-10&lt;/scalar&gt;
  &lt;scalar dataType="xsd:anyURI" title="CML site"&gt;http://www.xml-cml.org/&lt;/scalar&gt;
  &lt;scalar dataType="xsd:QName" title="CML atom"&gt;cml:atom&lt;/scalar&gt;
  &lt;scalar dataType="xsd:normalizedString" title="song"&gt;the mouse ran up the clock&lt;/scalar&gt;
  &lt;scalar dataType="xsd:language" title="UK English"&gt;en-GB&lt;/scalar&gt;
  &lt;scalar dataType="xsd:Name" title="atom"&gt;atom&lt;/scalar&gt;
  &lt;scalar dataType="xsd:ID" title="XML ID"&gt;_123&lt;/scalar&gt;
  &lt;scalar dataType="xsd:integer" title="the answer"&gt;42&lt;/scalar&gt;
  &lt;scalar dataType="xsd:nonPositiveInteger" title="zero"&gt;0&lt;/scalar&gt;
&lt;/list&gt;

           </pre>
        </div>
      </xsd:documentation>
    </xsd:annotation>
    <xsd:restriction base="xsd:string">
      <xsd:enumeration value="xsd:string"/>
      <xsd:enumeration value="xsd:boolean"/>
      <xsd:enumeration value="xsd:float"/>
      <xsd:enumeration value="xsd:double"/>
      <xsd:enumeration value="xsd:decimal"/>
      <xsd:enumeration value="xsd:duration"/>
      <xsd:enumeration value="xsd:dateTime"/>
      <xsd:enumeration value="xsd:time"/>
      <xsd:enumeration value="xsd:date"/>
      <xsd:enumeration value="xsd:gYearMonth"/>
      <xsd:enumeration value="xsd:gYear"/>
      <xsd:enumeration value="xsd:gMonthDay"/>
      <xsd:enumeration value="xsd:gDay"/>
      <xsd:enumeration value="xsd:gMonth"/>
      <xsd:enumeration value="xsd:hexBinary"/>
      <xsd:enumeration value="xsd:base64Binary"/>
      <xsd:enumeration value="xsd:anyURI"/>
      <xsd:enumeration value="xsd:QName"/>
      <xsd:enumeration value="xsd:NOTATION"/>
      <xsd:enumeration value="xsd:normalizedString"/>
      <xsd:enumeration value="xsd:token"/>
      <xsd:enumeration value="xsd:language"/>
      <xsd:enumeration value="xsd:IDREFS"/>
      <xsd:enumeration value="xsd:ENTITIES"/>
      <xsd:enumeration value="xsd:NMTOKEN"/>
      <xsd:enumeration value="xsd:NMTOKENS"/>
      <xsd:enumeration value="xsd:Name"/>
      <xsd:enumeration value="xsd:NCName"/>
      <xsd:enumeration value="xsd:ID"/>
      <xsd:enumeration value="xsd:IDREF"/>
      <xsd:enumeration value="xsd:ENTITY"/>
      <xsd:enumeration value="xsd:integer"/>
      <xsd:enumeration value="xsd:nonPositiveInteger"/>
      <xsd:enumeration value="xsd:negativeInteger"/>
      <xsd:enumeration value="xsd:long"/>
      <xsd:enumeration value="xsd:int"/>
      <xsd:enumeration value="xsd:short"/>
      <xsd:enumeration value="xsd:byte"/>
      <xsd:enumeration value="xsd:nonNegativeInteger"/>
      <xsd:enumeration value="xsd:unsignedLong"/>
      <xsd:enumeration value="xsd:unsignedInt"/>
      <xsd:enumeration value="xsd:unsignedShort"/>
      <xsd:enumeration value="xsd:unsignedByte"/>
      <xsd:enumeration value="xsd:positiveInteger"/>
    </xsd:restriction>
  </xsd:simpleType>
  <xsd:annotation>
    <xsd:documentation>
      <div class="summary">Array-based simpleTypes</div>
    </xsd:documentation>
  </xsd:annotation>
  <xsd:simpleType name="sizeType" id="st.sizeType">
    <xsd:annotation>
      <xsd:documentation>
        <div class="summary">The size of an array</div>
        <div class="description">
          <p>The size of an array. Redundant, but serves as a check
         for processing software (useful if delimiters are used)</p>
        </div>
      </xsd:documentation>
    </xsd:annotation>
    <xsd:restriction base="xsd:positiveInteger"/>
  </xsd:simpleType>
  <xsd:simpleType name="delimiterType" id="st.delimiterType">
    <xsd:annotation>
      <xsd:documentation>
        <div class="summary">A non-whitespace character used in arrays to separate components</div>
        <div class="description">
          <p>Some STM-ML elements (such as <a href="el.array">array</a>) have
        content representing concatenated values. The default separator is
        whitespace (which can be normalised) and this should be used whenever
        possible. However in some cases the values are empty, or contain whitespace or other
        problematic punctuation, and a delimiter is required.</p>
          <p>Note that the content string MUST start and end with the delimiter so
        there is no ambiguity as to what the components are. Only printable
        characters from the ASCII character set should be used, and character
        entities should be avoided.</p>
          <p>When delimiters are used to separate precise whitespace this should always
        consist of spaces and not the other allowed whitespace characters
        (newline, tabs, etc.). If the latter are important it is probably best to redesign
        the application.</p>
        </div>
        <div class="example">
          <pre>
&lt;array size="4" delimiter="|"&gt;|A|B12||D and   E|&lt;/array&gt;


 <em>The values in the array are</em>
  "A", "B12", "" (empty string) and "D and   E"
 <em>note the spaces</em>
          </pre>
        </div>
      </xsd:documentation>
    </xsd:annotation>
    <xsd:restriction base="xsd:string"/>
  </xsd:simpleType>
  <xsd:simpleType name="floatArrayType" id="st.floatArrayType">
    <xsd:annotation>
      <xsd:documentation>
        <div class="summary">An array of floats</div>
        <div class="description">
          <p>An array of floats or other real numbers.
            Not used in STM Schema, but re-used by CML.
            </p>
        </div>
        <div class="example">
          <pre>
&lt;atomArray xmlns="http://www.xml-cml.org/schema/core"
  x2="1.2 2.3 3.4 5.6"/&gt;

           </pre>
        </div>
      </xsd:documentation>
    </xsd:annotation>
    <xsd:list itemType="xsd:decimal"/>
  </xsd:simpleType>
  <xsd:simpleType name="matrixType" id="st.matrixType">
    <xsd:annotation>
      <xsd:documentation>
        <div class="summary">Allowed <a href="el.matrix">matrix</a> types</div>
        <div class="description">
          <p>Allowed <tt>matrix</tt> types.
       These are mainly square matrices</p>
        </div>
        <div class="example">
          <pre>
&lt;matrix id="m1" title="mattrix-1" dictRef="foo:bar"
  rows="3" columns="3" dataType="xsd:decimal"
  delimiter="|" matrixType="squareSymmetric" units="unit:m"
  &gt;|1.1|1.2|1.3|1.2|2.2|2.3|1.3|2.3|3.3!&lt;/matrix&gt;

      </pre>
        </div>
      </xsd:documentation>
    </xsd:annotation>
    <xsd:union>
      <xsd:simpleType>
        <xsd:restriction base="xsd:string">
          <xsd:enumeration value="rectangular"/>
          <xsd:enumeration value="square"/>
          <xsd:enumeration value="squareSymmetric"/>
          <xsd:enumeration value="squareAntisymmetric"/>
          <xsd:enumeration value="diagonal">
            <xsd:annotation>
              <xsd:documentation>
                <div class="description">Symmetric. Elements are zero except on the diagonal</div>
              </xsd:documentation>
            </xsd:annotation>
          </xsd:enumeration>
          <xsd:enumeration value="upperTriangular">
            <xsd:annotation>
              <xsd:documentation>
                <div class="description">Square. Elements are zero below the diagonal
            <pre>
1 2 3 4
0 3 5 6
0 0 4 8
0 0 0 2
      </pre>
                </div>
              </xsd:documentation>
            </xsd:annotation>
          </xsd:enumeration>
          <xsd:enumeration value="lowerTriangular">
            <xsd:annotation>
              <xsd:documentation>
                <div class="description">Symmetric. Elements are zero except on the diagonal</div>
              </xsd:documentation>
            </xsd:annotation>
          </xsd:enumeration>
          <xsd:enumeration value="unitary"/>
          <xsd:enumeration value="rowEigenvectors"/>
          <xsd:enumeration value="rotation22"/>
          <xsd:enumeration value="rotationTranslation32"/>
          <xsd:enumeration value="homogeneous33"/>
          <xsd:enumeration value="rotation33"/>
          <xsd:enumeration value="rotationTranslation43"/>
          <xsd:enumeration value="homogeneous44"/>
          <xsd:enumeration value="square"/>
          <xsd:enumeration value="square"/>
        </xsd:restriction>
      </xsd:simpleType>
      <xsd:simpleType>
        <xsd:restriction base="namespaceRefType"/>
      </xsd:simpleType>
    </xsd:union>
  </xsd:simpleType>
  <xsd:simpleType name="countType" id="st.countType">
    <xsd:annotation>
      <xsd:documentation>
        <div class="summary">
          <p>A count multiplier for certain elements</p>
        </div>
        <div class="description">
          <p>A count multiplier for certain elements, such as
            <tt>action</tt> or <tt>object</tt>.</p>
        </div>
        <div class="example">
          <pre>
&lt;list&gt;
&lt;object title="frog" count="10"/&gt;
&lt;action title="step3" count="3"&gt;
  &lt;p&gt;Add 10 ml reagent&lt;/p&gt;
&lt;/action&gt;
&lt;/list&gt;

           </pre>
        </div>
      </xsd:documentation>
    </xsd:annotation>
    <xsd:restriction base="xsd:integer">
      <xsd:minInclusive value="1"/>
      <xsd:maxInclusive value="999999999999"/>
    </xsd:restriction>
  </xsd:simpleType>
  <xsd:annotation>
    <xsd:documentation>
      <div class="summary">General simpleTypes</div>
    </xsd:documentation>
  </xsd:annotation>
  <xsd:simpleType name="idType" id="st.idType">
    <xsd:annotation>
      <xsd:documentation>
        <div class="summary">A unique ID for STM elements</div>
        <div class="description">
          <p>A unique ID for STM elements. This is not formally
          of type ID (an XML NAME which must start with a letter and contain only letters,
          digits and <tt>.-_:</tt>). It is recommended that IDs start with a letter,
          and contain no punctuation or whitespace. The function <tt>generate-id()</tt>
          in XSLT will generate semantically void unique IDs</p>.
          <p>It is difficult to ensure uniqueness when documents are merged. We suggest
          namespacing IDs, perhaps using the containing elements as the base.
          Thus <tt>mol3:a1</tt> could be a useful unique ID.
          However this is still experimental.</p>
        </div>
      </xsd:documentation>
    </xsd:annotation>
    <xsd:restriction base="xsd:string">
      <xsd:pattern value="[A-Za-z0-9_\-]+(:[A-Za-z0-9_\-]+)?"/>
    </xsd:restriction>
  </xsd:simpleType>
  <xsd:attributeGroup name="idGroup" id="attGp.id">
    <xsd:attribute name="id" type="idType" id="att.id">
      <xsd:annotation>
        <xsd:documentation>
          <div class="summary">A attribute prividing a unique ID for STM elements</div>
          <div class="description">
            <p>See <a href="st.idType">idType</a> for full documentation.</p>
          </div>
        </xsd:documentation>
      </xsd:annotation>
    </xsd:attribute>
  </xsd:attributeGroup>
  <xsd:attributeGroup name="titleGroup" id="attGp.title">
    <xsd:attribute name="title" type="xsd:string" id="att.title">
      <xsd:annotation>
        <xsd:documentation>
          <div class="summary">An (optional) title on most STM elements. Uncontrolled</div>
        </xsd:documentation>
      </xsd:annotation>
    </xsd:attribute>
  </xsd:attributeGroup>
  <xsd:attributeGroup name="convGroup" id="attGp.conv">
    <xsd:attribute name="convention" type="namespaceRefType" default="CML" id="att.convention">
      <xsd:annotation>
        <xsd:documentation>
          <div class="summary">A reference to a convention</div>
          <div class="description">
            <p>A reference to a convention which is inherited by all the subelements.</p>
            <p>It may be useful to create conventions with namespaces,
         </p>
            <p>this attribute is inherited by its child elements; thus a <tt>molecule</tt>
    with a convention sets the default for its bonds and atoms. This can be overwritten
    if necessary by an explicit <tt>convention</tt>.</p>
            <p>Use of convention will normally require non-STM-ML semantics, and should be used with
    caution. We would expect that conventions prefixed with "ISO" would be useful,
    such as ISO8601 for dateTimes.</p>
          </div>
          <div class="example">
            <pre>
&lt;bond convention="fooChem" order="-5"
   xmlns:fooChem="http://www.fooChem/conventions"/&gt;

     </pre>
          </div>
        </xsd:documentation>
      </xsd:annotation>
    </xsd:attribute>
  </xsd:attributeGroup>
  <xsd:annotation>
    <xsd:documentation>
      <div class="summary">Numeric types</div>
    </xsd:documentation>
  </xsd:annotation>
  <xsd:simpleType name="errorBasisType" id="st.errorBasisType">
    <xsd:annotation>
      <xsd:documentation>
        <div class="summary">The basis of an error value</div>
        <div class="description">
          <p>Errors in values can be of several types and this simpleType
         provides a small controlled vocabulary</p>
        </div>
        <div class="example">
          <pre>
&lt;scalar
    dataType="xsd:decimal"
    errorValue="1.0"
    errorBasis="observedStandardDeviation"
    title="body weight"
    dictRef="zoo:bodywt"
    units="units:g"&gt;34.3&lt;/scalar&gt;

           </pre>
        </div>
      </xsd:documentation>
    </xsd:annotation>
    <xsd:restriction base="xsd:string">
      <xsd:enumeration value="observedRange"/>
      <xsd:enumeration value="observedStandardDeviation"/>
      <xsd:enumeration value="observedStandardError"/>
      <xsd:enumeration value="estimatedStandardDeviation"/>
      <xsd:enumeration value="estimatedStandardError"/>
    </xsd:restriction>
  </xsd:simpleType>
  <xsd:simpleType name="maxType" id="st.maxType">
    <xsd:annotation>
      <xsd:documentation>
        <div class="summary">The maximum INCLUSIVE value of a quantity</div>
        <div class="description">
          <p>The maximum INCLUSIVE value of a sortable quantity such as
          numeric, date or string. It should be ignored for dataTypes such as URL.
          The use of <tt>min</tt> and
        <tt>max</tt> attributes can be used to give a range for the quantity.
       The statistical basis of this range is not defined. The value of <tt>max</tt>
       is usually an observed
       quantity (or calculated from observations). To restrict a value, the <tt>
       maxExclusive</tt> type in a dictionary should be used.</p>
          <p>The type of the maximum is the same as the quantity to which it refers - numeric,
       date and string are currently allowed</p>
        </div>
        <div class="example">
          <pre>&lt;scalar dataType="xsd:float" maxValue="20" minValue="12"&gt;15&lt;/scalar&gt;
</pre>
        </div>
      </xsd:documentation>
    </xsd:annotation>
    <xsd:restriction base="xsd:string"/>
  </xsd:simpleType>
  <xsd:simpleType name="minType" id="st.minType">
    <xsd:annotation>
      <xsd:documentation>
        <div class="summary">The minimum INCLUSIVE value of a quantity</div>
        <div class="description">
          <p>The minimum INCLUSIVE value of a sortable quantity such as
            numeric, date or string. It should be ignored for dataTypes such as URL.
            The use of <tt>min</tt> and
          <tt>min</tt> attributes can be used to give a range for the quantity.
         The statistical basis of this range is not defined. The value of <tt>min</tt>
         is usually an observed
         quantity (or calculated from observations). To restrict a value, the <tt>
         minExclusive</tt> type in a dictionary should be used.</p>
          <p>The type of the minimum is the same as the quantity to which it refers - numeric,
         date and string are currently allowed</p>
        </div>
        <div class="example">
          <pre>&lt;scalar dataType="xsd:float" maxValue="20" minValue="12"&gt;15&lt;/scalar&gt;
</pre>
        </div>
      </xsd:documentation>
    </xsd:annotation>
    <xsd:restriction base="xsd:string"/>
  </xsd:simpleType>
  <xsd:annotation>
    <xsd:documentation>
      <div class="subheading">Links and References</div>
    </xsd:documentation>
  </xsd:annotation>
  <xsd:element name="link" id="el.link">
    <xsd:annotation>
      <xsd:documentation>
        <div class="summary">An internal or external link to STMML or other object(s)</div>
        <div class="description">
          <p>
            <tt>link</tt> is an internal or external link to STMML or other object(s). </p>
          <p>
            <b>Semantics are similar to XLink, but simpler and only a subset is implemented.</b>
         This is intended to make the instances easy to create and read, and software
         relatively easy to implement. The architecture is:</p>
          <ul>
            <li>
              <b>A single element (<tt>link</tt>) used for all linking purposes</b>. </li>
            <li>
              <b>The link types are determined by the <tt>type</tt> attribute and can be:</b>.
        <ul>
                <li>
                  <b>locator</b>. This points to a single target and must carry either a <tt>ref</tt> or <tt>href</tt> attribute.
        <tt>locator</tt> links are usually children of an extended link.
        <li>
                    <b>arc</b>. This is a 1:1 link with both ends (<tt>from</tt> and <tt>to</tt>) defined.</li>
                  <li>
                    <b>extended</b>. This is usually a parent of several locator links and serves
        to create a grouping of link ends (i.e. a list of references in documents).</li>
        Many-many links can be built up from arcs linking extended elements</li>
              </ul>
              <p>All links can have optional <tt>role</tt> attributes. The semantics of this are not defined;
        you are encouraged to use a URI as described in the XLink specification.</p>
              <p>There are two address spaces: </p>
              <ul>
                <li>The <tt>href</tt> attribute on locators behaves in the same way as <tt>href</tt> in
        HTML and is of type <tt>xsd:anyURI</tt>. Its primary use is to use XPointer to reference
        elements outside the document.</li>
                <li>The <tt>ref</tt> attribute on locators and the <tt>from</tt> and <tt>to</tt>
        attributes on <tt>arc</tt>s refer to IDs (<em>without</em> the '#' syntax).</li>
              </ul>
              <p>Note: several other specific linking mechanisms are defined elsewhere in STM. <a href="         el.relatedEntry">relatedEntry</a> should be used in dictionaries, and <a href="st.dictRef">dictRef</a>
        should be used to link to dictionaries. There are no required uses of <tt>link</tt> in STM-ML
        but we have used it to map atoms, electrons and bonds in reactions in CML</p>
            </li>
          </ul>
          <p>
            <b>Relation to XLink</b>.
         At present (2002) we are not aware of generic XLink
         processors from which we would benefit, so the complete implementation brings little
         extra value.
         Among the simplifications from Xlink are:</p>
          <ul>
            <li>
              <tt>type</tt> supports only <tt>extended</tt>, <tt>locator</tt> and <tt>arc</tt>
            </li>
            <li>
              <tt>label</tt> is not supported and <tt>id</tt>s are used as targets of links.</li>
            <li>
              <tt>show</tt> and <tt>actuate</tt> are not supported.</li>
            <li>
              <tt>xlink:title</tt> is not supported (all STM elements can have a <tt>title</tt>
         attribute).</li>
            <li>
              <tt>xlink:role</tt> supports any string (i.e. does not have to be a namespaced resource).
         This mechanism can, of course, still be used and we shall promote it where STM
         benefits from it</li>
            <li>The <tt>to</tt> and <tt>from</tt> attributes point to IDs rather than labels</li>
            <li>The xlink namespace is not used</li>
            <li>It is not intended to create independent linkbases, although some collections of
         links may have this property and stand outside the documents they link to</li>
          </ul>
        </div>
      </xsd:documentation>
    </xsd:annotation>
    <xsd:complexType>
      <xsd:sequence>
        <xsd:any minOccurs="0" maxOccurs="unbounded"/>
      </xsd:sequence>
      <xsd:attributeGroup ref="tit_id_conv_dictGroup"/>
      <xsd:attribute name="from" type="namespaceRefType">
        <xsd:annotation>
          <xsd:documentation>
            <div class="summary">The starting point of an arc</div>
          </xsd:documentation>
        </xsd:annotation>
      </xsd:attribute>
      <xsd:attribute name="to" type="namespaceRefType">
        <xsd:annotation>
          <xsd:documentation>
            <div class="summary">The endpoint of an arc</div>
          </xsd:documentation>
        </xsd:annotation>
      </xsd:attribute>
      <xsd:attribute name="ref" type="namespaceRefType">
        <xsd:annotation>
          <xsd:documentation>
            <div class="summary">An ID referenced within a locator</div>
          </xsd:documentation>
        </xsd:annotation>
      </xsd:attribute>
      <xsd:attribute name="role" type="xsd:string">
        <xsd:annotation>
          <xsd:documentation>
            <div class="summary">The role of the link. Xlink adds semantics through a
          URI; we shall not be this strict. We shall not normally use this mechanism
          and use dictionaries instead</div>
          </xsd:documentation>
        </xsd:annotation>
      </xsd:attribute>
      <xsd:attribute name="href" type="xsd:anyURI">
        <xsd:annotation>
          <xsd:documentation>
            <div class="summary">The target of the (locator) link, outside the document</div>
          </xsd:documentation>
        </xsd:annotation>
      </xsd:attribute>
      <xsd:attribute name="type">
        <xsd:annotation>
          <xsd:documentation>
            <div class="summary">The type of the link</div>
          </xsd:documentation>
        </xsd:annotation>
        <xsd:simpleType>
          <xsd:restriction base="xsd:string">
            <xsd:enumeration value="extended">
              <xsd:annotation>
                <xsd:documentation>
                  <div class="summary">A container for locators</div>
                </xsd:documentation>
              </xsd:annotation>
            </xsd:enumeration>
            <xsd:enumeration value="locator">
              <xsd:annotation>
                <xsd:documentation>
                  <div class="summary">A link to an element</div>
                </xsd:documentation>
              </xsd:annotation>
            </xsd:enumeration>
            <xsd:enumeration value="arc">
              <xsd:annotation>
                <xsd:documentation>
                  <div class="summary">A labelled link</div>
                </xsd:documentation>
              </xsd:annotation>
            </xsd:enumeration>
          </xsd:restriction>
        </xsd:simpleType>
      </xsd:attribute>
    </xsd:complexType>
  </xsd:element>
  <xsd:annotation>
    <xsd:documentation>
      <div class="summary">References</div>
    </xsd:documentation>
  </xsd:annotation>
  <xsd:simpleType name="namespaceRefType" id="st.namespaceRefType">
    <xsd:annotation>
      <xsd:documentation>
        <div class="summary">
         A string referencing a dictionary, units, convention or other metadata.
      </div>
        <div class="description">
          <p>A string referencing a dictionary, units, convention or other
      metadata. The namespace is optional but recommended where possible</p>
          <p>Note: this convention is only used within STM-ML and related languages;
      it is NOT a URI.</p>
        </div>
        <div class="example">
          <pre>
&lt;list&gt;
&lt;!-- dictRef is of namespaceRefType --&gt;
  &lt;scalar dictRef="chem:mpt"&gt;123&lt;/scalar&gt;
&lt;!-- error --&gt;
  &lt;scalar dictRef="mpt23"&gt;123&lt;/scalar&gt;
&lt;/list&gt;

        </pre>
        </div>
      </xsd:documentation>
    </xsd:annotation>
    <xsd:restriction base="xsd:string">
      <xsd:pattern value="[A-Za-z][A-Za-z0-9_]*(:[A-Za-z][A-Za-z0-9_]*)?"/>
    </xsd:restriction>
  </xsd:simpleType>
  <xsd:simpleType name="refType" id="st.refType">
    <xsd:annotation>
      <xsd:documentation>
        <div class="summary">A reference to an existing element</div>
        <div class="description">
          <p>A reference to an existing element in the document.
            The target of the
            ref attribute (which may be namepsaced) must exist. The test for validity
            will normally occur in the element's <tt>appinfo</tt>
          </p>
          <p>Any DOM Node created from this element will normally be a <i>reference</i>
            to another Node, so that if the target node is modified a the dereferenced
            content is modified. At present there are no deep copy semantics hardcoded
            into the schema.</p>
        </div>
      </xsd:documentation>
    </xsd:annotation>
    <xsd:restriction base="idType"/>
  </xsd:simpleType>
  <xsd:annotation>
    <xsd:documentation>
      <div class="heading">General information components</div>
    </xsd:documentation>
  </xsd:annotation>
  <xsd:annotation>
    <xsd:documentation>
      <div class="heading">General components</div>
      <div class="description">
        <p>STM-ML provides a very small number of abstract elements to capture
    frequently encountered concepts in STM documents. There are no predetermined
    semantics or ontology; it is expected that descriptive metadata
    will be added through dictionaries.
    </p>
        <p>All elements can contain any element children and can carry the common
    STM attributes. Currently there are the following:</p>
        <ul>
          <li>
            <a href="el.object">object</a>. Almost anything - concrete, abstract, representable by
    a noun. Objects can have properties added through <a href="el.scalar">scalar</a>, etc.
    </li>
          <li>
            <a href="el.action">action</a>. Represents an action performed during a scientific narrative.
    It has attributes describing a time-line and conditions so that a procedure could be replayed.
    It has a container <a href="el.actionList">actionList</a> which shares these attributes
    and which can describe sets of actions.
    </li>
          <li>
            <a href="el.observation">observation</a>. Contains narrative or other elements describing
    an observation, planned or unplanned</li>
        </ul>
      </div>
    </xsd:documentation>
  </xsd:annotation>
  <xsd:element name="action" id="el.action">
    <xsd:annotation>
      <xsd:documentation>
        <div class="summary">An action which might occur in scientific data or narrative.</div>
        <div class="description">
          <p>An action which might occur in scientific data or narrative.
      The definition is deliberately vague, intending to collect examples of
      possible usage. Thus an action could be addition of materials,
      measurement, application of heat or radiation.
      The content model is unrestricted. <tt>action</tt> iself is
      normally a child of <a href="#el.actionList">actionList</a>
          </p>
          <p>The start, end and duration attributes should be interpreted as
      </p>
          <ul>
            <li>XSD dateTimes and XSD durations. This allows precise recording of
      time of day, etc, or duration
      after start of actionList. A <tt>convention="xsd"</tt> attribute should be used
      to enforce XSD.</li>
            <li>a numerical value, with a units attribute linked to a dictionary.</li>
            <li>a human-readable string (unlikely to be machine processable)</li>
          </ul>
          <p>
            <tt>startCondition</tt> and <tt>endCondition</tt>
      values are not constrained, which allows XSL-like <tt>test</tt> attribute values.
      The semantics of the conditions are yet to be defined and at present are simply
      human readable.
      </p>
          <p>The order of the <tt>action</tt> elements in the document may, but will not always, define
      the order that they actually occur in.</p>
          <p>A delay can be shown by an <tt>action</tt> with no content. Repeated actions or
      actionLists are indicated through the count attribute.</p>
        </div>
        <div class="example">
          <pre>
&lt;actionList title="boiling two eggs for breakfast"&gt;
  &lt;!-- start cooking at 9am --&gt;
  &lt;action title="turn on heat" start="T09:00:00" convention="xsd"/&gt;
  &lt;!-- human readable description of time to start action --&gt;
  &lt;action title="put egg into pan" startCondition="water is boiling" count="2"/&gt;
  &lt;!-- the duration is expressed in ISO8601 format --&gt;
  &lt;action title="boil eggs for 4 minutes" duration="4" units="units:min"/&gt;
  &lt;!-- action immediately follows last action --&gt;
  &lt;action title="remove egg from pan" count="1"/&gt;
  &lt;action title="boil second egg for a bit longer" duration="about half a minute"/&gt;
  &lt;!-- action immediately follows last action --&gt;
  &lt;action title="remove egg from pan" count="1"/&gt;
&lt;/actionList&gt;

         </pre>
        </div>
        <div class="example">
          <pre>
&lt;actionList title="preparation of silanols"&gt;
  &lt;p&gt;This is a conversion of a chemical synthesis to STM-ML. We
  have deliberately not marked up the chemistry in this example!&lt;/p&gt;
  &lt;action title="step2"&gt;
    &lt;p&gt;Take 1 mmol of the diol and dissolve in dioxan in
      &lt;object title="flask"&gt;
        &lt;scalar title="volume" units="units:ml"&gt;25&lt;/scalar&gt;
      &lt;/object&gt;
    &lt;/p&gt;
  &lt;/action&gt;
  &lt;action title="step2"&gt;
    &lt;p&gt;Place flask in water bath with magnetic stirrer&lt;/p&gt;
  &lt;/action&gt;
  &lt;!-- wait until certain condition --&gt;
  &lt;actionList endCondition="bath temperature stabilised"/&gt;
  &lt;action title="step3"&gt;
    &lt;p&gt;Add 0.5 ml 1 M H2SO4&lt;/p&gt;
  &lt;/action&gt;

  &lt;!-- carry out reaction --&gt;
  &lt;actionList endCondition="reaction complete; no diol spot remains on TLC"&gt;
    &lt;actionList title="check tlc"&gt;
      &lt;!-- wait for half an hour --&gt;
      &lt;action duration="half an hour"/&gt;
      &lt;action title="tlc"&gt;
        &lt;p&gt;extract solution and check diol spot on TLC&lt;/p&gt;
      &lt;/action&gt;
    &lt;/actionList&gt;
  &lt;/actionList&gt;

  &lt;!-- work up reaction --&gt;
  &lt;action title="step5"&gt;
    &lt;p&gt;Add 10 ml water to flask&lt;/p&gt;
  &lt;/action&gt;
  &lt;action title="step6"&gt;
    &lt;p&gt;Neutralize acid with 10% NaHCO3&lt;/p&gt;
  &lt;/action&gt;
  &lt;action title="step7" count="3"&gt;
    &lt;p&gt;Extract with 10ml ether&lt;/p&gt;
  &lt;/action&gt;
  &lt;action title="step8"&gt;
    &lt;p&gt;Combine ether layers&lt;/p&gt;
  &lt;/action&gt;
  &lt;action title="step9" count="2"&gt;
    &lt;p&gt;Wash ether with 10 ml water&lt;/p&gt;
  &lt;/action&gt;
  &lt;action title="step10"&gt;
    &lt;p&gt;Wash ether with 10 ml saturated NaCl&lt;/p&gt;
  &lt;/action&gt;
  &lt;action title="step11"&gt;
    &lt;p&gt;Dry over anhydrous Na2SO4 and remove solvent on rotary evaporator&lt;/p&gt;
  &lt;/action&gt;
&lt;/actionList&gt;

         </pre>
        </div>
      </xsd:documentation>
    </xsd:annotation>
    <xsd:complexType mixed="true">
      <xsd:sequence minOccurs="0" maxOccurs="unbounded">
        <xsd:any processContents="lax"/>
      </xsd:sequence>
      <xsd:attributeGroup ref="tit_id_conv_dictGroup"/>
      <xsd:attributeGroup ref="actionGroup"/>
      <xsd:attribute name="type" type="xsd:string">
        <xsd:annotation>
          <xsd:documentation>
            <div class="summary">The type of the action; semantics are not controlled.</div>
          </xsd:documentation>
        </xsd:annotation>
      </xsd:attribute>
    </xsd:complexType>
  </xsd:element>
  <xsd:element name="actionList" id="el.actionList">
    <xsd:annotation>
      <xsd:documentation>
        <div class="summary">A container for a group of <a href="el.action">actions</a>
        </div>
        <div class="description">
          <p>
            <tt>ActionList</tt> contains a series of <tt>action</tt>s or
        nested <tt>actionList</tt>s.</p>
        </div>
        <div class="example">See examples in <a href="el.action">action</a>
        </div>
        <div class="example">
          <pre>
&lt;!-- demonstrating parallel and sequential actions --&gt;
&lt;actionList order="parallel" endCondition="all food cooked"&gt;
  &lt;!-- meat and potatoes are cooked in parallel --&gt;
  &lt;actionList title="meat"&gt;
    &lt;action title="cook" endCondition="cooked"&gt;
      &lt;p&gt;Roast meat&lt;/p&gt;
    &lt;/action&gt;
    &lt;action&gt;&lt;p&gt;Keep warm in oven&lt;/p&gt;&lt;/action&gt;
  &lt;/actionList&gt;
  &lt;actionList title="vegetables"&gt;
    &lt;actionList title="cookVeg" endCondition="cooked"&gt;
      &lt;action title="boil water" endCondition="water boiling"&gt;
        &lt;p&gt;Heat water&lt;/p&gt;
      &lt;/action&gt;
      &lt;action title="cook" endCondition="potatoes cooked"&gt;
        &lt;p&gt;Cook potatoes&lt;/p&gt;
      &lt;/action&gt;
    &lt;/actionList&gt;
    &lt;action&gt;&lt;p&gt;Keep warm in oven&lt;/p&gt;&lt;/action&gt;
  &lt;/actionList&gt;
&lt;/actionList&gt;

        </pre>
        </div>
      </xsd:documentation>
    </xsd:annotation>
    <xsd:complexType mixed="true">
      <xsd:sequence minOccurs="0" maxOccurs="unbounded">
        <xsd:any processContents="lax"/>
      </xsd:sequence>
      <xsd:attributeGroup ref="tit_id_conv_dictGroup"/>
      <xsd:attributeGroup ref="actionGroup"/>
      <xsd:attribute name="type" type="xsd:string">
        <xsd:annotation>
          <xsd:documentation>
            <div class="summary">The type of the actionList; no defined semantics</div>
          </xsd:documentation>
        </xsd:annotation>
      </xsd:attribute>
      <xsd:attribute name="order" default="sequential">
        <xsd:annotation>
          <xsd:documentation>
            <div class="description">Describes whether child elements are sequential or parallel</div>
          </xsd:documentation>
        </xsd:annotation>
        <xsd:simpleType>
          <xsd:restriction base="xsd:string">
            <xsd:enumeration value="sequential"/>
            <xsd:enumeration value="parallel"/>
          </xsd:restriction>
        </xsd:simpleType>
      </xsd:attribute>
    </xsd:complexType>
  </xsd:element>
  <xsd:element name="object" id="el.object">
    <xsd:annotation>
      <xsd:documentation>
        <div class="summary">An object which might occur in scientific data or narrative</div>
        <div class="description">
          <p>Deliberately vague. Thus an instrument might be built from sub component
        objects, or a program could be composed of smaller modules (objects).
        Unrestricted content model</p>
        </div>
        <div class="example">
          <pre>&lt;object title="frog" type="amphibian" count="5"&gt;
  &lt;scalar dataType="xsd:float" title="length" units="unit:cm"&gt;5&lt;/scalar&gt;
  &lt;obj1/&gt;
&lt;/object&gt;
</pre>
        </div>
      </xsd:documentation>
    </xsd:annotation>
    <xsd:complexType mixed="true">
      <xsd:sequence minOccurs="0" maxOccurs="unbounded">
        <xsd:any processContents="lax"/>
      </xsd:sequence>
      <xsd:attributeGroup ref="tit_id_conv_dictGroup"/>
      <xsd:attribute name="type" type="xsd:string">
        <xsd:annotation>
          <xsd:documentation>
            <div class="summary">Type of the object. Uncontrolled semantics</div>
          </xsd:documentation>
        </xsd:annotation>
      </xsd:attribute>
      <xsd:attribute name="count" type="countType"/>
    </xsd:complexType>
  </xsd:element>
  <xsd:element name="observation" id="el.observation">
    <xsd:annotation>
      <xsd:documentation>
        <div class="summary">An observation or occurrence</div>
        <div class="description">
          <p>A container for any events that
        need to be recorded, whether planned or not. They can include notes,
        measurements, conditions that may be referenced elsewhere, etc. There are
        no controlled semantics </p>
          <div class="example">
            <pre>&lt;observation type="ornithology"&gt;
  &lt;object title="sparrow" count="3"/&gt;
  &lt;observ/&gt;
&lt;/observation&gt;
</pre>
          </div>
        </div>
      </xsd:documentation>
    </xsd:annotation>
    <xsd:complexType mixed="true">
      <xsd:sequence minOccurs="0" maxOccurs="unbounded">
        <xsd:any processContents="lax"/>
      </xsd:sequence>
      <xsd:attributeGroup ref="tit_id_conv_dictGroup"/>
      <xsd:attribute name="type" type="xsd:string">
        <xsd:annotation>
          <xsd:documentation>
            <div class="summary">Type of observation (uncontrolled vocabulary)</div>
          </xsd:documentation>
        </xsd:annotation>
      </xsd:attribute>
      <xsd:attribute name="count" type="countType"/>
    </xsd:complexType>
  </xsd:element>
  <xsd:element name="stmml" id="el.stmml">
    <xsd:annotation>
      <xsd:documentation>
        <div class="summary">An element to hold stmml data.</div>
        <div class="description">
          <p>
            <tt>stmml</tt> holds stmml data under a single
            generic container. Other namespaces may be present as children.
            No semantics implied.
         </p>
        </div>
        <div class="example">
          <pre>
&lt;stmml&gt;
  &lt;actionList&gt;
    &lt;action&gt;&lt;/action&gt;
  &lt;/actionList&gt;
  &lt;object&gt;&lt;/object&gt;
  &lt;observation&gt;&lt;/observation&gt;

&lt;!-- ==================== DICTIONARY =========== --&gt;

  &lt;dictionary&gt;
    &lt;annotation&gt;
      &lt;documentation&gt;&lt;/documentation&gt;
      &lt;appinfo&gt;&lt;/appinfo&gt;
    &lt;/annotation&gt;
    &lt;entry term="foo"&gt;
      &lt;definition&gt;&lt;/definition&gt;
      &lt;alternative&gt;&lt;/alternative&gt;
      &lt;description&gt;&lt;/description&gt;
      &lt;enumeration&gt;&lt;/enumeration&gt;
      &lt;relatedEntry&gt;&lt;/relatedEntry&gt;
    &lt;/entry&gt;
  &lt;/dictionary&gt;

&lt;!-- =================  METADATA ================== --&gt;

  &lt;metadataList&gt;
    &lt;metadata&gt;&lt;/metadata&gt;
  &lt;/metadataList&gt;

&lt;!-- =================  SCIENTIFIC UNITS ================== --&gt;

  &lt;unitList&gt;
    &lt;unitType id="ut1" name="u"&gt;
      &lt;dimension name="mass"&gt;&lt;/dimension&gt;
    &lt;/unitType&gt;
    &lt;unit id="u1"&gt;&lt;/unit&gt;
  &lt;/unitList&gt;

&lt;/stmml&gt;



        </pre>
        </div>
      </xsd:documentation>
    </xsd:annotation>
    <xsd:complexType>
      <xsd:sequence minOccurs="0" maxOccurs="unbounded">
        <xsd:any processContents="lax"/>
      </xsd:sequence>
      <xsd:attributeGroup ref="tit_id_conv_dictGroup"/>
    </xsd:complexType>
  </xsd:element>
  <xsd:annotation>
    <xsd:documentation>
      <div class="subheading">Dictionary components</div>
      <div class="description">
        <p>Dictionaries are a major part of STM-ML and supported as follows:</p>
        <p>The dictionary itself:</p>
        <ul>
          <li>
            <a href="el.dictionary">dictionary</a>. This element defines a dictionary
    and is often the root element (though a data instance might also be combined
    with a dictionary). The dictionary play a similar role to a simple schema, by defining
    data types and other constraints (such as enumerations). By transforming a dictionary to
    schema format, schema-based tools can be used for validation. A dictionary is
    normally composed of <a href="el.entry">entry</a>s.</li>
          <li>
            <a href="el.entry">entry</a>. An entry contanins information which <em>describes</em>
    or <em>constrains</em> elements in a data instance. The link is made through a
    <a href="st.dictRef">dictRef</a> attribute on the data element.
    Descriptive information can apply to any type of element (not necessarily
    part of or derived from the STM Schema). Constraints are similar to those in XML Schemas
    and use the same vocabulary (dataTypes, value ranges, enumerations, patterns, etc.). They normally
    apply to elements from the STM Schema or derived from it.<br/>
    In addition entrys can constrain elements to have the same
    higher-level structures and constraints defined by STM Schema. Thus entrys can require a
    data element to be a matrix, of a given type, with fixed number os rows and columns. These
    constraints are usually attributes on the entry element, which therefore maps
    directly onto the instance. Every entry has a mandatory <tt>term</tt> attribute
    which is the formal text string representing the concept. This string can contain any allowed
    XML characters (e.g. greek characters) but not markup (e.g. MathML or CML).</li>
          <li>
            <a href="el.definition">definition</a>. An almost mandatory child element of entry, giving
    a formal definition of the term</li>
          <li>
            <a href="el.description">description</a>. Additional descriptive informati&gt;on for an entry.
    This can contain any content, often HTML, but also MathML, CML for description of
    equations, chemical formulae, etc.</li>
          <li>
            <a href="el.alternative">alternative</a>. Alternative strings for describing the
    concept. These can be any of the stnadard lexical and terminological data categories
    such as synonyms, abbreviations, homonyms, etc. (see ISO12620 for a full range).</li>
          <li>
            <a href="el.enumeration">enumeration</a>. A list of allowed values for the data
    element (or elements in arrays, matrices).</li>
          <li>
            <a href="el.relatedEntry">relatedEntry</a>. A related entry. Sometimes this is
    descriptive (e.g. "seeAlso" provides additional information on related concepts).
    It can also be used for constraints, and there is a small controlled vocabulary
    of relationships, but no universal syntax. We
    support parentage (e.g. through "partitiveParent" = "partOf"). In principle this can
    be used with <a href="el.appinfo">appinfo</a> to provide algorithmically constructed
    relationships.
    </li>
          <li>
            <em>attributes</em>. A wide range of constraints is provided through attributes,
    several being similar to facets on XML Schema datatypes:
    <ul>
              <li>
                <b>rows</b> and <b>columns</b>, the structure of the data element.</li>
              <li>
                <b>recommendedUnits</b>, <b>units</b> and <b>unitType</b>, the units of the data element.</li>
              <li>
                <b>minExclusive</b>, <b>minInclusive</b>, <b>maxExclusive</b> and <b>maxInclusive</b>,
    the value of the data element.</li>
              <li>
                <b>totalDigits</b>, <b>fractionDigits</b>, <b>length</b>, <b>maxLength</b>, <b>minLength</b>
    and <b>pattern</b>. The lexical form of the  data element.</li>
            </ul>
          </li>
          <li>
            <a href="el.annotation">annotation</a>. Similar to XML Schema, this has children
    <a href="el.documentation">documentation</a> for information about the entry (normally
    curatorial) and <a href="el.appinfo">appinfo</a> to describe entries and constraints
    in machine-processable fashion.
    .</li>
        </ul>
      </div>
    </xsd:documentation>
  </xsd:annotation>
  <xsd:element name="dictionary" id="el.dictionary">
    <xsd:annotation>
      <xsd:documentation>
        <div class="summary">A dictionary</div>
        <div class="description">
          <p>A dictionary is a container for <a href="el.entry">entry</a>
        elements. Dictionaries can also contain unit-related information.</p>
          <p>The dictRef attribute on a <tt>dictionary</tt> element
         sets a namespace-like prefix allowing the dictionary to be referenced from
         within the document. In general dictionaries are
         referenced from an element using the
         <a href="gp.dictRefGroup">dictRef</a> attribute.</p>
        </div>
        <div class="example">
          <pre>
&lt;stm:dictionary xmlns:stm="http://www.xml-cml.org/schema/stmml-1.1"&gt;
  &lt;stm:entry id="a001" term="Amplitude for charge density mixing"
    dataType="stm:decimal"
    units="arbitrary"&gt;
    &lt;stm:annotation&gt;
      &lt;stm:documentation&gt;
        &lt;div class="summary"&gt;Amplitude for charge density mixing&lt;/div&gt;
        &lt;div class="description"&gt;Not yet filled in...&lt;/div&gt;
      &lt;/stm:documentation&gt;
    &lt;/stm:annotation&gt;
    &lt;stm:alternative type="abbreviation"&gt;CDMixAmp&lt;/stm:alternative&gt;
  &lt;/stm:entry&gt;
&lt;/stm:dictionary&gt;

        </pre>
        </div>
        <div class="example">
          <p>
            <tt>dictionary</tt> can be used in an instance
        document to reference the dictionary used. Example:</p>
          <pre>
&lt;list&gt;
  &lt;dictionary
     dictRef="core" href="../dictionary/coreDict.xml"/&gt;
&lt;/list&gt;

        </pre>
        </div>
      </xsd:documentation>
    </xsd:annotation>
    <xsd:complexType>
      <xsd:sequence>
        <xsd:element ref="unitList" minOccurs="0" maxOccurs="unbounded">
          <xsd:annotation>
            <xsd:documentation>
              <div class="description">
                <p>This is so that a reference to a UnitList can be put in a dictionary.</p>
              </div>
            </xsd:documentation>
          </xsd:annotation>
        </xsd:element>
        <xsd:element ref="annotation" minOccurs="0" maxOccurs="unbounded"/>
        <xsd:element ref="description" minOccurs="0" maxOccurs="unbounded"/>
        <xsd:element ref="entry" minOccurs="0" maxOccurs="unbounded"/>
      </xsd:sequence>
      <xsd:attributeGroup ref="tit_id_conv_dictGroup"/>
      <xsd:attribute name="href" type="xsd:anyURI">
        <xsd:annotation>
          <xsd:documentation>
            <div class="summary">URI giving the location of the document. Mandatory if <tt>dictRef</tt>
            present.
          </div>
          </xsd:documentation>
        </xsd:annotation>
      </xsd:attribute>
    </xsd:complexType>
  </xsd:element>
  <xsd:element name="entry" id="el.entry">
    <xsd:annotation>
      <xsd:documentation>
        <div class="summary">A dictionary entry</div>
        <div class="example">
          <pre>
&lt;entry id="a003" term="alpha"
  dataType="float"
  minInclusive="0.0"
  maxInclusive="180.0"
  recommendedUnits="degrees"&gt;
  &lt;definition&gt;The alpha cell angle&lt;/definition&gt;
&lt;/entry&gt;

         </pre>
        </div>
        <div class="example">
          <pre>
&lt;entry id="a003"
  term="matrix1"
  dataType="float"
  rows="3"
  columns="4"
  unitType="unit:length"
  minInclusive="0.0"
  maxInclusive="100.0"
  recommendedUnits="unit:m"
  totalDigits="8"
  fractionDigits="3"&gt;
    &lt;definition&gt;A matrix of lengths&lt;/definition&gt;
    &lt;description&gt;A data instance will have a matrix which points
  to this entry (e.g. dictRef="foo:matrix1"). The matrix must
  be 3*4, composed of floats in 8.3 format, of type length,
  values between 0 and 100 and with recommended units metres.
    &lt;/description&gt;
&lt;/entry&gt;

         </pre>
        </div>
      </xsd:documentation>
    </xsd:annotation>
    <xsd:complexType>
      <xsd:sequence>
        <xsd:element ref="definition" minOccurs="0"/>
        <xsd:choice minOccurs="0" maxOccurs="unbounded">
          <xsd:element ref="alternative"/>
          <xsd:element ref="annotation"/>
          <!-- <xsd:element ref="definition"/> -->
          <xsd:element ref="description"/>
          <xsd:element ref="enumeration"/>
          <xsd:element ref="relatedEntry"/>
        </xsd:choice>
      </xsd:sequence>
      <xsd:attributeGroup ref="tit_id_convGroup"/>
      <xsd:attribute name="dataType" type="xsd:string"/>
      <xsd:attribute name="rows" type="xsd:positiveInteger" default="1"/>
      <xsd:attribute name="columns" type="xsd:positiveInteger" default="1"/>
      <xsd:attribute name="recommendedUnits" type="unitsType"/>
      <xsd:attribute name="unitType" type="xsd:string"/>
      <xsd:attribute name="minExclusive" type="xsd:decimal"/>
      <xsd:attribute name="minInclusive" type="xsd:decimal"/>
      <xsd:attribute name="maxExclusive" type="xsd:decimal"/>
      <xsd:attribute name="maxInclusive" type="xsd:decimal"/>
      <xsd:attribute name="totalDigits" type="xsd:positiveInteger"/>
      <xsd:attribute name="fractionDigits" type="xsd:nonNegativeInteger"/>
      <xsd:attribute name="length" type="xsd:nonNegativeInteger"/>
      <xsd:attribute name="minLength" type="xsd:nonNegativeInteger"/>
      <xsd:attribute name="maxLength" type="xsd:positiveInteger"/>
      <xsd:attribute name="units" type="unitsType"/>
      <xsd:attribute name="whiteSpace" type="xsd:string"/>
      <xsd:attribute name="pattern" type="xsd:string"/>
      <xsd:attribute name="term" type="xsd:string" use="required"/>
    </xsd:complexType>
  </xsd:element>
  <xsd:element name="definition" id="el.definition">
    <xsd:annotation>
      <xsd:documentation>
        <div class="summary">
          <p>The definition for a dictionary entry, scientific units, etc.</p>
        </div>
        <div class="description">
          <p>The definition should be a short nounal phrase definining the
         subject of the entry. Definitions should not include commentary, implementations,
         equations or formulae (unless the subject is one of these) or examples. The
         <tt>description</tt> element can be used for these.</p>
          <p>The definition can be in any markup language, but normally XHTML will be used,
        perhaps with links to other XML namespaces such as CML for chemistry.</p>
        </div>
        <div class="example">
          <em>From the IUPAC Dictionary of Medicinal Chemistry</em>
          <br/>
          <pre>
&lt;entry id="a7" term="Allosteric enzyme"&gt;
  &lt;definition&gt;An &lt;a href="#e3"&gt;enzyme&lt;/a&gt;
that contains a region to which small, regulatory molecules
("effectors") may bind in addition to and separate from the
substrate binding site and thereby affect the catalytic
activity.
  &lt;/definition&gt;
  &lt;description&gt;On binding the effector, the catalytic activity of the
&lt;strong&gt;enzyme&lt;/strong&gt; towards the substrate may be enhanced, in
which case the effector is an activator, or reduced, in which case
it is a de-activator or inhibitor.
  &lt;/description&gt;
&lt;/entry&gt;

           </pre>
        </div>
      </xsd:documentation>
    </xsd:annotation>
    <xsd:complexType mixed="true">
      <xsd:sequence minOccurs="0" maxOccurs="unbounded">
        <xsd:any processContents="lax"/>
      </xsd:sequence>
      <xsd:attributeGroup ref="sourceGroup"/>
    </xsd:complexType>
  </xsd:element>
  <xsd:element name="description" id="el.description">
    <xsd:annotation>
      <xsd:documentation>
        <div class="summary">Descriptive information in a dictionary entry, etc.</div>
        <div class="description">
          <p>Entries should have at least one separate <a href="el.definition">definition</a>s.
         <tt>description</tt> is then used for most of the other information, including
         examples. The <tt>class</tt> attribute has an uncontrolled vocabulary and
         can be used to clarify the purposes of the <tt>description</tt>
         elements.</p>
        </div>
        <div class="example">
          <em>From IUPAC Dictionary of Medicinal Chemistry</em>
          <pre>
&lt;entry id="a7" term="Allosteric enzyme"&gt;
  &lt;definition&gt;An &lt;a href="#e3"&gt;enzyme&lt;/a&gt;
that contains a region to which small, regulatory molecules
("effectors") may bind in addition to and separate from the
substrate binding site and thereby affect the catalytic
activity.
  &lt;/definition&gt;
  &lt;description&gt;On binding the effector, the catalytic activity of the
&lt;strong&gt;enzyme&lt;/strong&gt; towards the substrate may be enhanced, in
which case the effector is an activator, or reduced, in which case
it is a de-activator or inhibitor.
  &lt;/description&gt;
&lt;/entry&gt;

           </pre>
        </div>
      </xsd:documentation>
    </xsd:annotation>
    <xsd:complexType mixed="true">
      <xsd:sequence minOccurs="0" maxOccurs="unbounded">
        <xsd:any processContents="lax"/>
      </xsd:sequence>
      <xsd:attributeGroup ref="sourceGroup"/>
      <xsd:attribute name="class" type="xsd:string">
        <xsd:annotation>
          <xsd:documentation>
            <div class="description">
              <p>The type of this information. This is not controlled, but examples
            might include:</p>
              <ul>
                <li>description</li>
                <li>summary</li>
                <li>note</li>
                <li>usage</li>
                <li>qualifier</li>
              </ul>
            </div>
          </xsd:documentation>
        </xsd:annotation>
      </xsd:attribute>
    </xsd:complexType>
  </xsd:element>
  <xsd:element name="enumeration" id="el.enumeration">
    <xsd:annotation>
      <xsd:documentation>
        <div class="summary">An enumeration of string values associated
        with an <a href="el.entry">entry</a>
        </div>
        <div class="description">
          <p>An enumeration of string values. Used where a dictionary entry constrains
        the possible values in a document instance. The dataTypes (if any) must all be
        identical and are defined by the dataType of the containing element.</p>
        </div>
        <div class="example">
          <pre>
&lt;entry term="crystal system" id="cryst1" dataType="string"&gt;
  &lt;definition&gt;A crystal system&lt;/definition&gt;
  &lt;enumeration value="triclinic"&gt;
    &lt;annotation&gt;
      &lt;documentation&gt;
        &lt;div class="summary"&gt;No constraints on lengths and angles&lt;/div&gt;
      &lt;/documentation&gt;
    &lt;/annotation&gt;
  &lt;/enumeration&gt;
  &lt;enumeration value="monoclinic"&gt;
    &lt;annotation&gt;
      &lt;documentation&gt;
        &lt;div class="summary"&gt;Two cell angles are right angles; no other constraints&lt;/div&gt;
      &lt;/documentation&gt;
    &lt;/annotation&gt;
  &lt;/enumeration&gt;
  &lt;enumeration value="orthorhombic"&gt;
    &lt;annotation&gt;
      &lt;documentation&gt;
        &lt;div class="summary"&gt;All three angles are right angles; no other constraints&lt;/div&gt;
      &lt;/documentation&gt;
    &lt;/annotation&gt;
  &lt;/enumeration&gt;
  &lt;enumeration value="tetragonal"&gt;
    &lt;annotation&gt;
      &lt;documentation&gt;
        &lt;div class="summary"&gt;Fourfold axis of symmetry; All three angles are right angles; two equal cell lengths; no other constraints&lt;/div&gt;
      &lt;/documentation&gt;
    &lt;/annotation&gt;
  &lt;/enumeration&gt;
  &lt;enumeration value="trigonal"&gt;
    &lt;annotation&gt;
      &lt;documentation&gt;
        &lt;div class="summary"&gt;Threefold axis of symmetry; Two angles are right angles; one is 120 degrees; two equal lengths; no other constraints&lt;/div&gt;
      &lt;/documentation&gt;
    &lt;/annotation&gt;
  &lt;/enumeration&gt;
  &lt;enumeration value="hexagonal"&gt;
    &lt;annotation&gt;
      &lt;documentation&gt;
        &lt;div class="summary"&gt;Sixfold axis of symmetry; Two angles are right angles; one is 120 degrees; two equal lengths; no other constraints&lt;/div&gt;
      &lt;/documentation&gt;
    &lt;/annotation&gt;
  &lt;/enumeration&gt;
  &lt;enumeration value="cubic"&gt;
    &lt;annotation&gt;
      &lt;documentation&gt;
        &lt;div class="summary"&gt;All three angles are right angles; all cell lengths are equal&lt;/div&gt;
      &lt;/documentation&gt;
    &lt;/annotation&gt;
  &lt;/enumeration&gt;
&lt;/entry&gt;

           </pre>
        </div>
        <div class="description">
          <p>An enumeration of string values. The dataTypes (if any) must all be
        identical and are defined by the dataType of the containing element.</p>
          <p>Documentation can be added through an <a href="el.enumeration">enumeration</a>
        child</p>
        </div>
      </xsd:documentation>
    </xsd:annotation>
    <xsd:complexType>
      <xsd:sequence>
        <xsd:element ref="annotation" minOccurs="0"/>
      </xsd:sequence>
      <xsd:attribute name="value" type="xsd:string">
        <xsd:annotation>
          <xsd:documentation>
            <div class="summary">The value of the enumerated element.</div>
            <div class="description">
            Must be compatible
            with the dataType of the containing element (not schema-checkable directly
            but possible if dictionary is transformed to schema).</div>
          </xsd:documentation>
        </xsd:annotation>
      </xsd:attribute>
    </xsd:complexType>
  </xsd:element>
  <xsd:element name="alternative" id="el.alternative">
    <xsd:annotation>
      <xsd:documentation>
        <div class="summary">
          <p>An alternative name for an entry</p>
        </div>
        <div class="description">
          <p>At present a child of <a href="#el.entry">entry</a> which represents
           an alternative string that refers to the concept. There is a partial controlled
           vocabulary in <tt>alternativeType</tt> with values such as :
         </p>
          <ul>
            <li>synonym</li>
            <li>acronym</li>
            <li>abbreviation</li>
          </ul>
        </div>
        <div class="example">
          <pre>
 &lt;entry term="ammonia" id="a1"&gt;
   &lt;alternative type="synonym"&gt;Spirits of hartshorn&lt;/alternative&gt;
   &lt;alternative type="my:formula"&gt;NH3&lt;/alternative&gt;
 &lt;/entry&gt;

        </pre>
        </div>
      </xsd:documentation>
    </xsd:annotation>
    <xsd:complexType>
      <xsd:annotation>
        <xsd:documentation>
          <div class="summary">the type of an
          <a href="#el.alternative">alternative</a> element.
        </div>
          <div class="description">
            <p>
              <tt>alternativeType</tt> represents a the type of an
            <a href="#el.alternative">alternative</a> element.
          </p>
          </div>
        </xsd:documentation>
      </xsd:annotation>
      <xsd:simpleContent>
        <xsd:extension base="xsd:string">
          <xsd:attribute name="type">
            <xsd:simpleType>
              <xsd:union>
                <xsd:simpleType>
                  <xsd:restriction base="xsd:string">
                    <xsd:enumeration value="synonym"/>
                    <xsd:enumeration value="quasi-synonym"/>
                    <xsd:enumeration value="acronym"/>
                    <xsd:enumeration value="abbreviation"/>
                    <xsd:enumeration value="homonym"/>
                    <xsd:enumeration value="identifier"/>
                  </xsd:restriction>
                </xsd:simpleType>
                <xsd:simpleType>
                  <xsd:restriction base="namespaceRefType"/>
                </xsd:simpleType>
              </xsd:union>
            </xsd:simpleType>
          </xsd:attribute>
        </xsd:extension>
      </xsd:simpleContent>
    </xsd:complexType>
  </xsd:element>
  <xsd:element name="relatedEntry" id="el.relatedEntry">
    <xsd:annotation>
      <xsd:documentation>
        <div class="summary">An entry related in some way to a dictionary entry, scientific units, etc.</div>
        <div class="description">
          <p>The range of relationships is not restricted
        but should include parents, aggregation, seeAlso
        etc. dataCategories from ISO12620 can be referenced through the <tt>namespaced</tt>
        mechanism.</p>
        </div>
        <div class="example">
          <pre>
&lt;stm:entry id="a14" term="Autoreceptor"
  xmlns:stm="http://www.xml-cml.org/schema/core"&gt;
  &lt;stm:definition&gt;An &lt;strong&gt;autoreceptor&lt;/strong&gt;, present at a nerve ending, is
    a &lt;a href="#r1"&gt;receptor&lt;/a&gt;
    that regulates, via positive or negative feedback processes, the
    synthesis and/or release of its own physiological ligand.
  &lt;/stm:definition&gt;
  &lt;stm:relatedEntry type="seeAlso" href="#h4"&gt;Heteroreceptor).&lt;/stm:relatedEntry&gt;
  &lt;stm:relatedEntry type="my:antonym" href="#h4"&gt;antiheteroreceptor).&lt;/stm:relatedEntry&gt;
  &lt;relatedEntry1/&gt;
&lt;/stm:entry&gt;

               </pre>
        </div>
      </xsd:documentation>
    </xsd:annotation>
    <xsd:complexType mixed="true">
      <xsd:attribute name="type">
        <xsd:simpleType>
          <xsd:annotation>
            <xsd:documentation>
              <div class="description">
                <p>
                  <tt>relatedEntryType</tt> represents a the type of relationship in a
                     <a href="#el.relatedEntry">relatedEntry</a> element.
                  </p>
              </div>
            </xsd:documentation>
          </xsd:annotation>
          <xsd:union>
            <xsd:simpleType>
              <xsd:restriction base="xsd:string">
                <xsd:enumeration value="parent"/>
                <xsd:enumeration value="partitiveParent"/>
                <xsd:enumeration value="child"/>
                <xsd:enumeration value="partitiveChild"/>
                <xsd:enumeration value="related"/>
                <xsd:enumeration value="synonym"/>
                <xsd:enumeration value="quasi-synonym"/>
                <xsd:enumeration value="antonym"/>
                <xsd:enumeration value="homonym"/>
                <xsd:enumeration value="see"/>
                <xsd:enumeration value="seeAlso"/>
                <xsd:enumeration value="abbreviation"/>
                <xsd:enumeration value="acronym"/>
              </xsd:restriction>
            </xsd:simpleType>
            <xsd:simpleType>
              <xsd:restriction base="namespaceRefType"/>
            </xsd:simpleType>
          </xsd:union>
        </xsd:simpleType>
      </xsd:attribute>
      <xsd:attribute name="href" type="xsd:anyURI"/>
    </xsd:complexType>
  </xsd:element>
  <xsd:element name="annotation" id="el.annotation">
    <xsd:annotation>
      <xsd:documentation>
        <div class="summary">
          <p>A documentation container similar to <tt>annotation</tt> in XML Schema.</p>
        </div>
        <div class="description">
          <p>A documentation container similar to <tt>annotation</tt> in XML Schema.
        At present this is experimental and designed to be used for dictionaries, units, etc.
        One approach is to convert these into XML Schemas when the <tt>documentation</tt>
        and <tt>appinfo</tt> children will emerge in their correct position in the
        derived schema.</p>
          <p>It is possible that this may develop as a useful tool for annotating components
        of complex objects such as molecules. </p>
        </div>
        <div class="example">
          <pre>
&lt;entry term="matrix"&gt;
  &lt;annotation&gt;
    &lt;documentation&gt;This refers to mathematical matrices&lt;/documentation&gt;
    &lt;appinfo&gt;... some code to describe and support matrices ...&lt;/appinfo&gt;
  &lt;/annotation&gt;
&lt;/entry&gt;

           </pre>
        </div>
      </xsd:documentation>
    </xsd:annotation>
    <xsd:complexType mixed="true">
      <xsd:choice minOccurs="0" maxOccurs="unbounded">
        <xsd:element ref="documentation"/>
        <xsd:element ref="appinfo"/>
      </xsd:choice>
      <xsd:attribute name="source" type="xsd:anyURI"/>
    </xsd:complexType>
  </xsd:element>
  <xsd:element name="documentation" id="el.documentation">
    <xsd:annotation>
      <xsd:documentation>
        <div class="summary">Documentation in the <a href="el.annotation">annotation</a> of an <a href="el.entry">entry</a>
        </div>
        <div class="description">
          <p>A container similar to <tt>documentation</tt> in XML Schema.
        This is NOT part of the textual content of an entry but is designed to
        support the transformation of dictionary entrys into schemas for validation.
        This is experimental and should only be used for dictionaries, units, etc.
        One approach is to convert these into XML Schemas when the <tt>documentation</tt>
        and <tt>appinfo</tt> children will emerge in their correct position in the
        derived schema.</p>
          <p>Do NOT confuse documentation with the <a href="el.definition">definition</a>
        or the <a href="el.definition">definition</a> which are part of the content
        of the dictionary</p>
          <p>If will probably only be used when there is significant <a href="el.appinfo">appinfo</a>
        in the entry or where the entry defines an XSD-like datatype of an element in the document.</p>
        </div>
        <div class="example">
          <pre>
&lt;stm:documentation id="source"
xmlns:stm="http://www.xml-cml.org/schema/stmml-1.1"&gt;
Transcribed from IUPAC website
&lt;/stm:documentation&gt;

           </pre>
        </div>
      </xsd:documentation>
    </xsd:annotation>
    <xsd:complexType mixed="true">
      <xsd:sequence minOccurs="0" maxOccurs="unbounded">
        <xsd:any processContents="lax"/>
      </xsd:sequence>
      <xsd:attributeGroup ref="sourceGroup"/>
      <xsd:attributeGroup ref="idGroup"/>
    </xsd:complexType>
  </xsd:element>
  <xsd:element name="appinfo" id="el.appinfo">
    <xsd:annotation>
      <xsd:documentation>
        <div class="summary">
          <p>A container similar to <tt>appinfo</tt> in XML Schema.</p>
        </div>
        <div class="description">
          <p>A container for machine processable documentation for an entry.
           This is likely to be platform and/or language specific. It is possible
           that XSLT, RDF or XBL will emerge as generic languages</p>
          <p>See <a href="el.annotation">annotation</a> and <a href="el.documentation">documentation</a> for further information</p>
        </div>
        <div class="example">
          <p>An example in XSLT where an element <tt>foo</tt> calls a bespoke
         template</p>.
         <pre>
&lt;s:appinfo
  xmlns:s="http://www.xml-cml.org/schema/core"
  xmlns="http://www.w3.org/1999/XSL/Transform"&gt;
  &lt;template match="foo"&gt;
    &lt;call-template name="processFoo"/&gt;
  &lt;/template&gt;
&lt;/s:appinfo&gt;

         </pre>
        </div>
      </xsd:documentation>
    </xsd:annotation>
    <xsd:complexType mixed="true">
      <xsd:sequence minOccurs="0" maxOccurs="unbounded">
        <xsd:any processContents="lax"/>
      </xsd:sequence>
      <xsd:attribute name="source" type="xsd:anyURI"/>
    </xsd:complexType>
  </xsd:element>
  <xsd:attributeGroup name="dictRefGroup" id="attGp.dictRefGroup">
    <xsd:attribute name="dictRef" type="namespaceRefType" id="att.dictRef">
      <xsd:annotation>
        <xsd:documentation>
          <div class="summary">
            <p>A reference to a dictionary entry.</p>
          </div>
          <div class="description">
            <p>Elements in data instances such as <a href="el.scalar">scalar</a> may have a
         <tt>dictRef</tt> attribute to point to an entry in a dictionary. To avoid
         excessive use of (mutable) filenames and URIs we recommend a namespace
         prefix, mapped to a namespace URI in the normal manner. In this case,
         of course, the namespace URI must point to a real XML document containing
         <a href="el.entry">entry</a> elements and validated against STM-ML Schema.</p>
            <p>Where there is concern about the dictionary becoming separated from the document
         the dictionary entries can be physically included as part of the data instance
         and the normal XPointer addressing mechanism can be used.</p>
            <p>This attribute can also be used on <a href="el.dictionary">dictionary</a>
         elements to define the namespace prefix</p>
          </div>
          <div class="example">
            <pre>
&lt;scalar dataType="xsd:float" title="surfaceArea"
  dictRef="cmlPhys:surfArea"
  xmlns:cmlPhys="http://www.xml-cml.org/dict/physical"
  units="units:cm2"&gt;50&lt;/scalar&gt;

           </pre>
          </div>
          <div class="example">
            <pre>
&lt;stm:list xmlns:stm="http://www.xml-cml.org/schema/stmml-1.1"&gt;
  &lt;stm:observation&gt;
    &lt;p&gt;We observed &lt;object count="3" dictRef="#p1"/&gt;
      constructing dwellings of different material&lt;/p&gt;
  &lt;/stm:observation&gt;
  &lt;stm:entry id="p1" term="pig"&gt;
    &lt;stm:definition&gt;A domesticated animal.&lt;/stm:definition&gt;
    &lt;stm:description&gt;Predators include wolves&lt;/stm:description&gt;
    &lt;stm:description class="scientificName"&gt;Sus scrofa&lt;/stm:description&gt;
  &lt;/stm:entry&gt;
&lt;/stm:list&gt;

           </pre>
          </div>
        </xsd:documentation>
      </xsd:annotation>
    </xsd:attribute>
  </xsd:attributeGroup>
  <xsd:annotation>
    <xsd:documentation>
      <div class="subheading">Metadata</div>
      <div class="description">
        <p>STM-ML supports metadata through the element
    <a href="el.metadata">metadata</a>. If necessary
    several of these can be contained in
    a <a href="el.metadataList">metadataList</a> element.
    </p>
      </div>
    </xsd:documentation>
  </xsd:annotation>
  <xsd:element name="metadata" id="el.metadata">
    <xsd:annotation>
      <xsd:documentation>
        <div class="summary">A general container for metadata</div>
        <div class="description">
          <p>A general container for metadata, including at least
      Dublin Core (DC) and CML-specific metadata</p>
          <p>In its simple form each element provides a name and content in a similar
      fashion to the <tt>meta</tt> element in HTML. <tt>metadata</tt> may have simpleContent
      (i.e. a string for adding further information - this is not controlled).</p>
        </div>
        <div class="example">
          <pre>
&lt;list&gt;
  &lt;metadataList&gt;
    &lt;metadata name="dc:coverage" content="Europe"/&gt;
    &lt;metadata name="dc:description" content="Ornithological chemistry"/&gt;
    &lt;metadata name="dc:identifier"  content="ISBN:1234-5678"/&gt;
    &lt;metadata name="dc:format" content="printed"/&gt;
    &lt;metadata name="dc:relation" content="abc:def123"/&gt;
    &lt;metadata name="dc:rights" content="licence:GPL"/&gt;
    &lt;metadata name="dc:subject" content="Informatics"/&gt;
    &lt;metadata name="dc:title" content="birds"/&gt;
    &lt;metadata name="dc:type" content="bird books on chemistry"/&gt;
    &lt;metadata name="dc:contributor" content="Tux Penguin"/&gt;
    &lt;metadata name="dc:creator" content="author"/&gt;
    &lt;metadata name="dc:publisher" content="Penguinone publishing"/&gt;
    &lt;metadata name="dc:source" content="penguinPub"/&gt;
    &lt;metadata name="dc:language" content="en-GB"/&gt;
    &lt;metadata name="dc:date" content="1752-09-10"/&gt;
  &lt;/metadataList&gt;
  &lt;metadataList&gt;
    &lt;metadata name="cmlm:safety" content="mostly harmless"/&gt;
    &lt;metadata name="cmlm:insilico" content="electronically produced"/&gt;
    &lt;metadata name="cmlm:structure" content="penguinone"/&gt;
    &lt;metadata name="cmlm:reaction" content="synthesis of penguinone"/&gt;
    &lt;metadata name="cmlm:identifier" content="smiles:O=C1C=C(C)C(C)(C)C(C)=C1"/&gt;
  &lt;/metadataList&gt;
&lt;/list&gt;
</pre>
        </div>
      </xsd:documentation>
    </xsd:annotation>
    <xsd:complexType>
      <xsd:simpleContent>
        <xsd:extension base="xsd:string">
          <xsd:attribute name="name" type="metadataType">
            <xsd:annotation>
              <xsd:documentation>
                <div class="summary">The metadata type</div>
              </xsd:documentation>
            </xsd:annotation>
          </xsd:attribute>
          <xsd:attribute name="content" type="xsd:string">
            <xsd:annotation>
              <xsd:documentation>
                <div class="summary">The metadata</div>
              </xsd:documentation>
            </xsd:annotation>
          </xsd:attribute>
        </xsd:extension>
      </xsd:simpleContent>
    </xsd:complexType>
  </xsd:element>
  <xsd:element name="metadataList" id="el.metadataList">
    <xsd:annotation>
      <xsd:documentation>
        <div class="summary">A general container for metadata elements</div>
        <div class="example">
          <pre>&lt;list&gt;
  &lt;metadataList&gt;
    &lt;metadata name="dc:coverage" content="Europe"/&gt;
    &lt;metadata name="dc:description" content="Ornithological chemistry"/&gt;
    &lt;metadata name="dc:identifier"  content="ISBN:1234-5678"/&gt;
    &lt;metadata name="dc:format" content="printed"/&gt;
    &lt;metadata name="dc:relation" content="abc:def123"/&gt;
    &lt;metadata name="dc:rights" content="licence:GPL"/&gt;
    &lt;metadata name="dc:subject" content="Informatics"/&gt;
    &lt;metadata name="dc:title" content="birds"/&gt;
    &lt;metadata name="dc:type" content="bird books on chemistry"/&gt;
    &lt;metadata name="dc:contributor" content="Tux Penguin"/&gt;
    &lt;metadata name="dc:creator" content="author"/&gt;
    &lt;metadata name="dc:publisher" content="Penguinone publishing"/&gt;
    &lt;metadata name="dc:source" content="penguinPub"/&gt;
    &lt;metadata name="dc:language" content="en-GB"/&gt;
    &lt;metadata name="dc:date" content="1752-09-10"/&gt;
  &lt;/metadataList&gt;
  &lt;metadataList&gt;
    &lt;metadata name="cmlm:safety" content="mostly harmless"/&gt;
    &lt;metadata name="cmlm:insilico" content="electronically produced"/&gt;
    &lt;metadata name="cmlm:structure" content="penguinone"/&gt;
    &lt;metadata name="cmlm:reaction" content="synthesis of penguinone"/&gt;
    &lt;metadata name="cmlm:identifier" content="smiles:O=C1C=C(C)C(C)(C)C(C)=C1"/&gt;
  &lt;/metadataList&gt;
&lt;/list&gt;
</pre>
        </div>
      </xsd:documentation>
    </xsd:annotation>
    <xsd:complexType>
      <xsd:sequence>
        <xsd:element ref="metadata" maxOccurs="unbounded"/>
      </xsd:sequence>
    </xsd:complexType>
  </xsd:element>
  <xsd:simpleType name="metadataType" id="md.metadataType">
    <xsd:restriction base="xsd:string">
      <xsd:enumeration value="dc:coverage">
        <xsd:annotation>
          <xsd:documentation>
            <div class="definition">The extent or scope of the
            content of the resource.</div>
            <div class="description">Coverage will typically include
            spatial location (a place name or geographic
            coordinates), temporal period (a period label, date, or
            date range) or jurisdiction (such as a named
            administrative entity). Recommended best practice is to
            select a value from a controlled vocabulary (for
            example, the Thesaurus of Geographic Names [TGN]) and
            that, where appropriate, named places or time periods
            be used in preference to numeric identifiers such as
            sets of coordinates or date ranges.
          </div>
          </xsd:documentation>
        </xsd:annotation>
      </xsd:enumeration>
      <xsd:enumeration value="dc:description">
        <xsd:annotation>
          <xsd:documentation>
            <div class="definition">An account of the content of the
            resource.</div>
            <div class="description">Description may include but is not
            limited to: an abstract, table of contents, reference
            to a graphical representation of content or a free-text
            account of the content.
          </div>
          </xsd:documentation>
        </xsd:annotation>
      </xsd:enumeration>
      <xsd:enumeration value="dc:identifier">
        <xsd:annotation>
          <xsd:documentation>
            <div class="definition">An unambiguous reference to the
            resource within a given context.</div>
            <div class="description">Recommended best practice is to
            identify the resource by means of a string or number
            conforming to a formal identification system. Example
            formal identification systems include the Uniform
            Resource Identifier (URI) (including the Uniform
            Resource Locator (URL)), the Digital Object Identifier
            (DOI) and the International Standard Book Number
            (ISBN).
          </div>
          </xsd:documentation>
        </xsd:annotation>
      </xsd:enumeration>
      <xsd:enumeration value="dc:format">
        <xsd:annotation>
          <xsd:documentation>
            <div class="definition">The physical or digital
            manifestation of the resource.</div>
            <div class="description">Typically, Format may include the
            media-type or dimensions of the resource. Format may be
            used to determine the software, hardware or other
            equipment needed to display or operate the resource.
            Examples of dimensions include size and duration.
            Recommended best practice is to select a value from a
            controlled vocabulary (for example, the list of
            Internet Media Types [MIME] defining computer media
            formats).
          </div>
          </xsd:documentation>
        </xsd:annotation>
      </xsd:enumeration>
      <xsd:enumeration value="dc:relation">
        <xsd:annotation>
          <xsd:documentation>
            <div class="definition">A reference to a related
            resource.</div>
            <div class="description">Recommended best practice is to
            reference the resource by means of a string or number
            conforming to a formal identification system.
          </div>
          </xsd:documentation>
        </xsd:annotation>
      </xsd:enumeration>
      <xsd:enumeration value="dc:rights">
        <xsd:annotation>
          <xsd:documentation>
            <div class="definition">Information about rights held in
            and over the resource.</div>
            <div class="description">Typically, a Rights element will
            contain a rights management statement for the resource,
            or reference a service providing such information.
            Rights information often encompasses Intellectual
            Property Rights (IPR), Copyright, and various Property
            Rights. If the Rights element is absent, no assumptions
            can be made about the status of these and other rights
            with respect to the resource.
          </div>
          </xsd:documentation>
        </xsd:annotation>
      </xsd:enumeration>
      <xsd:enumeration value="dc:subject">
        <xsd:annotation>
          <xsd:documentation>
            <div class="definition">The topic of the content of the
            resource.</div>
            <div class="description">Typically, a Subject will be
            expressed as keywords, key phrases or classification
            codes that describe a topic of the resource.
            Recommended best practice is to select a value from a
            controlled vocabulary or formal classification
            scheme.
          </div>
          </xsd:documentation>
        </xsd:annotation>
      </xsd:enumeration>
      <xsd:enumeration value="dc:title">
        <xsd:annotation>
          <xsd:documentation>
            <div class="definition">A name given to the resource.</div>
            <div class="description">Typically, a Title will be a name by
            which the resource is formally known.
          </div>
          </xsd:documentation>
        </xsd:annotation>
      </xsd:enumeration>
      <xsd:enumeration value="dc:type">
        <xsd:annotation>
          <xsd:documentation>
            <div class="definition">The nature or genre of the
            content of the resource.</div>
            <div class="description">Type includes terms describing
            general categories, functions, genres, or aggregation
            levels for content. Recommended best practice is to
            select a value from a controlled vocabulary (for
            example, the working draft list of Dublin Core Types
            [DCT1]). To describe the physical or digital
            manifestation of the resource, use the FORMAT
            element.
          </div>
          </xsd:documentation>
        </xsd:annotation>
      </xsd:enumeration>
      <xsd:enumeration value="dc:contributor">
        <xsd:annotation>
          <xsd:documentation>
            <div class="definition">An entity responsible for making
            contributions to the content of the resource.</div>
            <div class="description">Examples of a Contributor include a
            person, an organisation, or a service. Typically, the
            name of a Contributor should be used to indicate the
            entity.
          </div>
          </xsd:documentation>
        </xsd:annotation>
      </xsd:enumeration>
      <xsd:enumeration value="dc:creator">
        <xsd:annotation>
          <xsd:documentation>
            <div class="definition">An entity primarily responsible
            for making the content of the resource.</div>
            <div class="description">Examples of a Creator include a
            person, an organisation, or a service. Typically, the
            name of a Creator should be used to indicate the
            entity.
          </div>
          </xsd:documentation>
        </xsd:annotation>
      </xsd:enumeration>
      <xsd:enumeration value="dc:publisher">
        <xsd:annotation>
          <xsd:documentation>
            <div class="definition">An entity responsible for making
            the resource available</div>
            <div class="description">Examples of a Publisher include a
            person, an organisation, or a service. Typically, the
            name of a Publisher should be used to indicate the
            entity.
          </div>
          </xsd:documentation>
        </xsd:annotation>
      </xsd:enumeration>
      <xsd:enumeration value="dc:source">
        <xsd:annotation>
          <xsd:documentation>
            <div class="definition">A Reference to a resource from
            which the present resource is derived.</div>
            <div class="description">The present resource may be derived
            from the Source resource in whole or in part.
            Recommended best practice is to reference the resource
            by means of a string or number conforming to a formal
            identification system.
          </div>
          </xsd:documentation>
        </xsd:annotation>
      </xsd:enumeration>
      <xsd:enumeration value="dc:language">
        <xsd:annotation>
          <xsd:documentation>
            <div class="definition">A language of the intellectual
            content of the resource.</div>
            <div class="description">Recommended best practice for the
            values of the Language element is defined by RFC 1766
            [RFC1766] which includes a two-letter Language Code
            (taken from the ISO 639 standard [ISO639]), followed
            optionally, by a two-letter Country Code (taken from
            the ISO 3166 standard [ISO3166]). For example, 'en' for
            English, 'fr' for French, or 'en-uk' for English used
            in the United Kingdom.
          </div>
          </xsd:documentation>
        </xsd:annotation>
      </xsd:enumeration>
      <xsd:enumeration value="dc:date">
        <xsd:annotation>
          <xsd:documentation>
            <div class="definition">A date associated with an event
            in the life cycle of the resource.</div>
            <div class="description">Typically, Date will be associated
            with the creation or availability of the resource.
            Recommended best practice for encoding the date value
            is defined in a profile of ISO 8601 [W3CDTF] and
            follows the YYYY-MM-DD format.
          </div>
          </xsd:documentation>
        </xsd:annotation>
      </xsd:enumeration>
      <xsd:enumeration value="cmlm:safety">
        <xsd:annotation>
          <xsd:documentation>
            <div class="definition">Entry contains information
            relating to chemical safety</div>
            <div class="description">Typically the content will be a
            reference to a handbook, MSDS, threshhold or other
            human-readable string
          </div>
          </xsd:documentation>
        </xsd:annotation>
      </xsd:enumeration>
      <xsd:enumeration value="cmlm:insilico">
        <xsd:annotation>
          <xsd:documentation>
            <div class="definition">Part or whole of the information
            was computer-generated</div>
            <div class="description">Typically the content will be the
            name of a method or a program
          </div>
          </xsd:documentation>
        </xsd:annotation>
      </xsd:enumeration>
      <xsd:enumeration value="cmlm:structure">
        <xsd:annotation>
          <xsd:documentation>
            <div class="definition">3D structure included</div>
            <div class="description">details included
          </div>
          </xsd:documentation>
        </xsd:annotation>
      </xsd:enumeration>
      <xsd:enumeration value="cmlm:reaction"/>
      <xsd:enumeration value="cmlm:identifier"/>
      <xsd:enumeration value="other"/>
    </xsd:restriction>
  </xsd:simpleType>
  <xsd:annotation>
    <xsd:documentation>
      <div class="heading">Scientific Units</div>
    </xsd:documentation>
  </xsd:annotation>
  <xsd:element name="dimension" id="el.dimension">
    <xsd:annotation>
      <xsd:documentation>
        <div class="summary">A dimension supporting scientific units</div>
        <div class="description">
          <p>This will be primarily used within the defintion of
        <a href="el.unit">units</a>s.</p>
        </div>
        <div class="example">
          <pre>
&lt;unitType id="energy" name="energy"&gt;
  &lt;dimension name="length"/&gt;
  &lt;dimension name="mass"/&gt;
  &lt;dimension name="time" power="-1"/&gt;
&lt;/unitType&gt;


       </pre>
        </div>
      </xsd:documentation>
    </xsd:annotation>
    <xsd:complexType>
      <xsd:sequence/>
      <xsd:attribute name="name" type="dimensionType" use="required">
        <xsd:annotation>
          <xsd:documentation>
            <div class="summary">The type of the dimension</div>
          </xsd:documentation>
        </xsd:annotation>
      </xsd:attribute>
      <xsd:attribute name="power" type="xsd:decimal" default="1">
        <xsd:annotation>
          <xsd:documentation>
            <div class="summary">The power to which the dimension should be raised</div>
          </xsd:documentation>
        </xsd:annotation>
      </xsd:attribute>
    </xsd:complexType>
  </xsd:element>
  <xsd:simpleType name="dimensionType" id="st.dimensionType">
    <xsd:annotation>
      <xsd:documentation>
        <div class="summary">Allowed values for dimension Types (for quantities).</div>
        <div class="description">
          <p>These are the 7 types prescribed by the SI system, together
         with the "dimensionless" type. We intend to be somewhat uncoventional
         and explore enhanced values of "dimensionless", such as "angle".
         This may be heretical, but we find the present system impossible to implement
         in many cases.</p>
          <p>Used for constructing entries in a dictionary of units</p>
        </div>
        <div class="example">
          <pre>
&lt;unitType id="energy" name="energy"&gt;
  &lt;dimension name="length"/&gt;
  &lt;dimension name="mass"/&gt;
  &lt;dimension name="time" power="-1"/&gt;
&lt;/unitType&gt;

        </pre>
        </div>
      </xsd:documentation>
    </xsd:annotation>
    <xsd:restriction base="xsd:string">
      <xsd:enumeration value="mass"/>
      <xsd:enumeration value="length"/>
      <xsd:enumeration value="time"/>
      <xsd:enumeration value="current"/>
      <xsd:enumeration value="amount"/>
      <xsd:enumeration value="luminosity"/>
      <xsd:enumeration value="temperature"/>
      <xsd:enumeration value="dimensionless"/>
      <xsd:enumeration value="angle">
        <xsd:annotation>
          <xsd:documentation>
            <div class="summary">An angle (formally dimensionless, but useful to have units).</div>
          </xsd:documentation>
        </xsd:annotation>
      </xsd:enumeration>
    </xsd:restriction>
  </xsd:simpleType>
  <xsd:element name="unitList" id="el.unitList">
    <xsd:annotation>
      <xsd:documentation>
        <div class="summary">A container for several unit entries</div>
        <div class="description">Usually forms the complete units dictionary (along with metadata)</div>
        <div class="example">
          <pre>&lt;stm:unitList xmlns:stm="http://www.xml-cml.org/schema/stmml-1.1"&gt;

&lt;!-- ======================================================================= --&gt;
&lt;!-- ========================= fundamental types =========================== --&gt;
&lt;!-- ======================================================================= --&gt;

&lt;stm:unitType id="length" name="length"&gt;
  &lt;stm:dimension name="length"/&gt;
&lt;/stm:unitType&gt;

&lt;stm:unitType id="time" name="time"&gt;
  &lt;stm:dimension name="time"/&gt;
&lt;/stm:unitType&gt;

&lt;!-- ... --&gt;

&lt;stm:unitType id="dimensionless" name="dimensionless"&gt;
  &lt;stm:dimension name="dimensionless"/&gt;
&lt;/stm:unitType&gt;

&lt;!-- ======================================================================= --&gt;
&lt;!-- ========================== derived types ============================== --&gt;
&lt;!-- ======================================================================= --&gt;

&lt;stm:unitType id="acceleration" name="acceleration"&gt;
  &lt;stm:dimension name="length"/&gt;
  &lt;stm:dimension name="time" power="-2"/&gt;
&lt;/stm:unitType&gt;

&lt;!-- ... --&gt;

&lt;!-- ======================================================================= --&gt;
&lt;!-- ====================== fundamental SI units =========================== --&gt;
&lt;!-- ======================================================================= --&gt;

&lt;stm:unit id="second" name="second" unitType="time"&gt;
  &lt;stm:description&gt;The SI unit of time&lt;/stm:description&gt;
&lt;/stm:unit&gt;

&lt;stm:unit id="meter" name="meter" unitType="length"
  abbreviation="m"&gt;
  &lt;stm:description&gt;The SI unit of length&lt;/stm:description&gt;
&lt;/stm:unit&gt;

&lt;!-- ... --&gt;

&lt;stm:unit id="kg" name="nameless" unitType="dimensionless"
  abbreviation="nodim"&gt;
  &lt;stm:description&gt;A fictitious parent for dimensionless units&lt;/stm:description&gt;
&lt;/stm:unit&gt;

&lt;!-- ======================================================================= --&gt;
&lt;!-- ===================== derived SI units ================================ --&gt;
&lt;!-- ======================================================================= --&gt;

&lt;stm:unit id="newton" name="newton" unitType="force"&gt;
  &lt;stm:description&gt;The SI unit of force&lt;/stm:description&gt;
&lt;/stm:unit&gt;

&lt;!-- ... --&gt;

&lt;!-- multiples of fundamental SI units --&gt;

&lt;stm:unit id="g" name="gram" unitType="mass"
  parentSI="kg"
  multiplierToSI="0.001"
  abbreviation="g"&gt;
  &lt;stm:description&gt;0.001 kg. &lt;/stm:description&gt;
&lt;/stm:unit&gt;

&lt;stm:unit id="celsius" name="Celsius" parentSI="k"
  multiplierToSI="1"
  constantToSI="273.18"&gt;
  &lt;stm:description&gt;&lt;p&gt;A common unit of temperature&lt;/p&gt;&lt;/stm:description&gt;
&lt;/stm:unit&gt;

&lt;!-- fundamental non-SI units --&gt;

&lt;stm:unit id="inch" name="inch" parentSI="meter"
   abbreviation="in"
  multiplierToSI="0.0254" &gt;
  &lt;stm:description&gt;An imperial measure of length&lt;/stm:description&gt;
&lt;/stm:unit&gt;

&lt;!-- derived non-SI units --&gt;

&lt;stm:unit id="l" name="litre" unitType="volume"
   parentSI="meterCubed"
   abbreviation="l"
   multiplierToSI="0.001"&gt;
  &lt;stm:description&gt;Nearly 1 dm**3 This is not quite exact&lt;/stm:description&gt;
&lt;/stm:unit&gt;

&lt;!-- ... --&gt;

&lt;stm:unit id="fahr" name="fahrenheit" parentSI="k"
   abbreviation="F"
  multiplierToSI="0.55555555555555555"
  constantToSI="-17.777777777777777777"&gt;
  &lt;stm:description&gt;An obsolescent unit of temperature still used in popular
  meteorology&lt;/stm:description&gt;
&lt;/stm:unit&gt;

&lt;/stm:unitList&gt;
</pre>
        </div>
        <div class="example">
          <pre>&lt;stm:unitList
    xmlns:stm="http://www.xml-cml.org/schema/stmml-1.1"
    dictRef="unit" href="units.xml" /&gt;
</pre>
        </div>
      </xsd:documentation>
    </xsd:annotation>
    <xsd:complexType>
      <xsd:sequence>
        <xsd:element ref="unitType" minOccurs="0" maxOccurs="unbounded"/>
        <xsd:element ref="unit" minOccurs="0" maxOccurs="unbounded"/>
      </xsd:sequence>
      <xsd:attributeGroup ref="tit_id_conv_dictGroup"/>
      <xsd:attribute name="href" type="xsd:anyURI">
        <xsd:annotation>
          <xsd:documentation>
            <div class="summary">Maps a <a href="st.dictRefType">dictRef</a>
            prefix to the location of a dictionary.</div>
            <div class="description">This requires the prefix and the physical URI
            address to be contained within the same file. We can anticipate that
            better mechanisms will arise - perhaps through XMLCatalogs.
            At least it works at present.</div>
          </xsd:documentation>
        </xsd:annotation>
      </xsd:attribute>
    </xsd:complexType>
  </xsd:element>
  <xsd:element name="unitType" id="el.unitType">
    <xsd:annotation>
      <xsd:documentation>
        <div class="summary">An element containing the description of a scientific unit</div>
        <div class="description">
          <p>Mandatory for SI Units,
          optional for nonSI units since they should be able to obtain this
          from their parent. For complex derived units without parents it may be
          useful.</p>
          <p>Used within a unitList</p>
          <p>Distinguish carefully from <a href="st.unitsType">unitsType</a>
          which is primarily used for attributes describing the units that elements
          carry</p>
        </div>
        <div class="example">
          <pre>&lt;stm:unitList xmlns:stm="http://www.xml-cml.org/schema/stmml-1.1"&gt;

&lt;!-- ======================================================================= --&gt;
&lt;!-- ========================= fundamental types =========================== --&gt;
&lt;!-- ======================================================================= --&gt;

&lt;stm:unitType id="length" name="length"&gt;
  &lt;stm:dimension name="length"/&gt;
&lt;/stm:unitType&gt;

&lt;stm:unitType id="time" name="time"&gt;
  &lt;stm:dimension name="time"/&gt;
&lt;/stm:unitType&gt;

&lt;!-- ... --&gt;

&lt;stm:unitType id="dimensionless" name="dimensionless"&gt;
  &lt;stm:dimension name="dimensionless"/&gt;
&lt;/stm:unitType&gt;

&lt;!-- ======================================================================= --&gt;
&lt;!-- ========================== derived types ============================== --&gt;
&lt;!-- ======================================================================= --&gt;

&lt;stm:unitType id="acceleration" name="acceleration"&gt;
  &lt;stm:dimension name="length"/&gt;
  &lt;stm:dimension name="time" power="-2"/&gt;
&lt;/stm:unitType&gt;

&lt;!-- ... --&gt;

&lt;!-- ======================================================================= --&gt;
&lt;!-- ====================== fundamental SI units =========================== --&gt;
&lt;!-- ======================================================================= --&gt;

&lt;stm:unit id="second" name="second" unitType="time"&gt;
  &lt;stm:description&gt;The SI unit of time&lt;/stm:description&gt;
&lt;/stm:unit&gt;

&lt;stm:unit id="meter" name="meter" unitType="length"
  abbreviation="m"&gt;
  &lt;stm:description&gt;The SI unit of length&lt;/stm:description&gt;
&lt;/stm:unit&gt;

&lt;!-- ... --&gt;

&lt;stm:unit id="kg" name="nameless" unitType="dimensionless"
  abbreviation="nodim"&gt;
  &lt;stm:description&gt;A fictitious parent for dimensionless units&lt;/stm:description&gt;
&lt;/stm:unit&gt;

&lt;!-- ======================================================================= --&gt;
&lt;!-- ===================== derived SI units ================================ --&gt;
&lt;!-- ======================================================================= --&gt;

&lt;stm:unit id="newton" name="newton" unitType="force"&gt;
  &lt;stm:description&gt;The SI unit of force&lt;/stm:description&gt;
&lt;/stm:unit&gt;

&lt;!-- ... --&gt;

&lt;!-- multiples of fundamental SI units --&gt;

&lt;stm:unit id="g" name="gram" unitType="mass"
  parentSI="kg"
  multiplierToSI="0.001"
  abbreviation="g"&gt;
  &lt;stm:description&gt;0.001 kg. &lt;/stm:description&gt;
&lt;/stm:unit&gt;

&lt;stm:unit id="celsius" name="Celsius" parentSI="k"
  multiplierToSI="1"
  constantToSI="273.18"&gt;
  &lt;stm:description&gt;&lt;p&gt;A common unit of temperature&lt;/p&gt;&lt;/stm:description&gt;
&lt;/stm:unit&gt;

&lt;!-- fundamental non-SI units --&gt;

&lt;stm:unit id="inch" name="inch" parentSI="meter"
   abbreviation="in"
  multiplierToSI="0.0254" &gt;
  &lt;stm:description&gt;An imperial measure of length&lt;/stm:description&gt;
&lt;/stm:unit&gt;

&lt;!-- derived non-SI units --&gt;

&lt;stm:unit id="l" name="litre" unitType="volume"
   parentSI="meterCubed"
   abbreviation="l"
   multiplierToSI="0.001"&gt;
  &lt;stm:description&gt;Nearly 1 dm**3 This is not quite exact&lt;/stm:description&gt;
&lt;/stm:unit&gt;

&lt;!-- ... --&gt;

&lt;stm:unit id="fahr" name="fahrenheit" parentSI="k"
   abbreviation="F"
  multiplierToSI="0.55555555555555555"
  constantToSI="-17.777777777777777777"&gt;
  &lt;stm:description&gt;An obsolescent unit of temperature still used in popular
  meteorology&lt;/stm:description&gt;
&lt;/stm:unit&gt;

&lt;/stm:unitList&gt;
</pre>
        </div>
      </xsd:documentation>
    </xsd:annotation>
    <xsd:complexType>
      <xsd:sequence>
        <xsd:element ref="dimension" minOccurs="0" maxOccurs="unbounded"/>
      </xsd:sequence>
      <xsd:attribute name="id" type="idType" use="required"/>
      <xsd:attribute name="name" type="xsd:string" use="required"/>
    </xsd:complexType>
  </xsd:element>
  <xsd:element name="unit" id="el.unit">
    <xsd:annotation>
      <xsd:documentation>
        <div class="summary">A scientific unit</div>
        <div class="description">
          <p>A scientific unit. Units are of the following types:</p>
          <ul>
            <li>SI Units. These may be one of the seven fundamental types
        (e.g. meter) or may be derived (e.g. joule). An SI unit is
        identifiable because it has no parentSI attribute and will have
        a unitType attribute.</li>
            <li>nonSI Units. These will normally have a parent SI unit
        (e.g. calorie has joule as an SI parent). </li>
            <li/>
          </ul>
          <p>Example:</p>
          <pre>
&lt;unit id="units:fahr" name="fahrenheit" parentSI="units:K"
  multiplierToSI="0.55555555555555555"
  constantToSI="-17.777777777777777777"&gt;
    &lt;description&gt;An obsolescent unit of temperature still used in popular
      meteorology&lt;/description&gt;
&lt;/unit&gt;

        </pre>
        </div>
      </xsd:documentation>
      <xsd:appinfo>

      </xsd:appinfo>
    </xsd:annotation>
    <xsd:complexType>
      <xsd:choice minOccurs="0" maxOccurs="unbounded">
        <xsd:element ref="description"/>
        <xsd:element ref="annotation"/>
      </xsd:choice>
      <xsd:attribute name="id" type="xsd:string" use="required"/>
      <xsd:attribute name="abbreviation" type="xsd:string"/>
      <xsd:attribute name="name" type="xsd:string"/>
      <xsd:attribute name="parentSI" type="xsd:string">
        <xsd:annotation>
          <xsd:documentation>
            <div class="summary">
        A reference to the parent SI unit (forbidden for SI Units themselves).
          </div>
          </xsd:documentation>
        </xsd:annotation>
      </xsd:attribute>
      <xsd:attribute name="unitType" type="xsd:string">
        <xsd:annotation>
          <xsd:documentation>
            <div class="summary">
        A reference to the unitType (required for SI Units).
          </div>
          </xsd:documentation>
        </xsd:annotation>
      </xsd:attribute>
      <xsd:attribute name="multiplierToSI" type="xsd:decimal" default="1">
        <xsd:annotation>
          <xsd:documentation>
            <div class="summary">
              <p>The factor by which the non-SI unit should be multiplied to
        convert a quantity to its representation in SI Units.
        This is applied <b>before</b>
                <tt>constantToSI</tt>.
        Mandatory for nonSI units; forbidden for SI units</p>
            </div>
          </xsd:documentation>
        </xsd:annotation>
      </xsd:attribute>
      <xsd:attribute name="constantToSI" type="xsd:decimal" default="0">
        <xsd:annotation>
          <xsd:documentation>
            <div class="summary">
              <p>The amount to add to a quantity in non-SI units to
    convert its representation to SI Units.
    This is applied <b>after</b>
                <tt>multiplierToSI</tt>.
    Optional for nonSI units; forbidden for SI units.
  </p>
            </div>
          </xsd:documentation>
        </xsd:annotation>
      </xsd:attribute>
    </xsd:complexType>
  </xsd:element>
  <xsd:simpleType name="unitsType" id="st.unitsType">
    <xsd:annotation>
      <xsd:documentation>
        <div class="summary">Scientific units</div>
        <div class="description">
          <p>Scientific units. These will be linked to dictionaries of units with
         conversion information, using namespaced references (e.g. <tt>si:m</tt>)
          </p>
          <p>Distinguish carefully from <a href="st.unitType">unitType</a>
          which is an element describing a type of a unit in a <a href="el.unitList">unitList</a>
          </p>
        </div>
        <div class="example">
          <pre>&lt;stm:unitList xmlns:stm="http://www.xml-cml.org/schema/stmml-1.1"&gt;

&lt;!-- ======================================================================= --&gt;
&lt;!-- ========================= fundamental types =========================== --&gt;
&lt;!-- ======================================================================= --&gt;

&lt;stm:unitType id="length" name="length"&gt;
  &lt;stm:dimension name="length"/&gt;
&lt;/stm:unitType&gt;

&lt;stm:unitType id="time" name="time"&gt;
  &lt;stm:dimension name="time"/&gt;
&lt;/stm:unitType&gt;

&lt;!-- ... --&gt;

&lt;stm:unitType id="dimensionless" name="dimensionless"&gt;
  &lt;stm:dimension name="dimensionless"/&gt;
&lt;/stm:unitType&gt;

&lt;!-- ======================================================================= --&gt;
&lt;!-- ========================== derived types ============================== --&gt;
&lt;!-- ======================================================================= --&gt;

&lt;stm:unitType id="acceleration" name="acceleration"&gt;
  &lt;stm:dimension name="length"/&gt;
  &lt;stm:dimension name="time" power="-2"/&gt;
&lt;/stm:unitType&gt;

&lt;!-- ... --&gt;

&lt;!-- ======================================================================= --&gt;
&lt;!-- ====================== fundamental SI units =========================== --&gt;
&lt;!-- ======================================================================= --&gt;

&lt;stm:unit id="second" name="second" unitType="time"&gt;
  &lt;stm:description&gt;The SI unit of time&lt;/stm:description&gt;
&lt;/stm:unit&gt;

&lt;stm:unit id="meter" name="meter" unitType="length"
  abbreviation="m"&gt;
  &lt;stm:description&gt;The SI unit of length&lt;/stm:description&gt;
&lt;/stm:unit&gt;

&lt;!-- ... --&gt;

&lt;stm:unit id="kg" name="nameless" unitType="dimensionless"
  abbreviation="nodim"&gt;
  &lt;stm:description&gt;A fictitious parent for dimensionless units&lt;/stm:description&gt;
&lt;/stm:unit&gt;

&lt;!-- ======================================================================= --&gt;
&lt;!-- ===================== derived SI units ================================ --&gt;
&lt;!-- ======================================================================= --&gt;

&lt;stm:unit id="newton" name="newton" unitType="force"&gt;
  &lt;stm:description&gt;The SI unit of force&lt;/stm:description&gt;
&lt;/stm:unit&gt;

&lt;!-- ... --&gt;

&lt;!-- multiples of fundamental SI units --&gt;

&lt;stm:unit id="g" name="gram" unitType="mass"
  parentSI="kg"
  multiplierToSI="0.001"
  abbreviation="g"&gt;
  &lt;stm:description&gt;0.001 kg. &lt;/stm:description&gt;
&lt;/stm:unit&gt;

&lt;stm:unit id="celsius" name="Celsius" parentSI="k"
  multiplierToSI="1"
  constantToSI="273.18"&gt;
  &lt;stm:description&gt;&lt;p&gt;A common unit of temperature&lt;/p&gt;&lt;/stm:description&gt;
&lt;/stm:unit&gt;

&lt;!-- fundamental non-SI units --&gt;

&lt;stm:unit id="inch" name="inch" parentSI="meter"
   abbreviation="in"
  multiplierToSI="0.0254" &gt;
  &lt;stm:description&gt;An imperial measure of length&lt;/stm:description&gt;
&lt;/stm:unit&gt;

&lt;!-- derived non-SI units --&gt;

&lt;stm:unit id="l" name="litre" unitType="volume"
   parentSI="meterCubed"
   abbreviation="l"
   multiplierToSI="0.001"&gt;
  &lt;stm:description&gt;Nearly 1 dm**3 This is not quite exact&lt;/stm:description&gt;
&lt;/stm:unit&gt;

&lt;!-- ... --&gt;

&lt;stm:unit id="fahr" name="fahrenheit" parentSI="k"
   abbreviation="F"
  multiplierToSI="0.55555555555555555"
  constantToSI="-17.777777777777777777"&gt;
  &lt;stm:description&gt;An obsolescent unit of temperature still used in popular
  meteorology&lt;/stm:description&gt;
&lt;/stm:unit&gt;

&lt;/stm:unitList&gt;
</pre>
        </div>
      </xsd:documentation>
    </xsd:annotation>
    <xsd:restriction base="xsd:string"/>
  </xsd:simpleType>
  <xsd:annotation>
    <xsd:documentation>
      <div class="heading">Groups (for schema maintenance and re-use)</div>
    </xsd:documentation>
  </xsd:annotation>
  <xsd:attributeGroup name="actionGroup" id="attGp.action">
    <xsd:attribute name="start" type="xsd:string">
      <xsd:annotation>
        <xsd:documentation>
          <div class="summary">The start time</div>
          <div class="description">
            <p>The start time in any allowable XSD representation of date, time or dateTime.
          This will normally be a clock time or date.</p>
          </div>
        </xsd:documentation>
      </xsd:annotation>
    </xsd:attribute>
    <xsd:attribute name="startCondition" type="xsd:string"/>
    <xsd:attribute name="duration" type="xsd:string"/>
    <xsd:attribute name="end" type="xsd:string">
      <xsd:annotation>
        <xsd:documentation>
          <div class="summary">The end time</div>
          <div class="description">
            <p>The start time in any allowable XSD representation of date, time or dateTime.
          This will normally be a clock time or date.</p>
          </div>
        </xsd:documentation>
      </xsd:annotation>
    </xsd:attribute>
    <xsd:attribute name="endCondition" type="xsd:string">
      <xsd:annotation>
        <xsd:documentation>
          <div class="summary">
            <p>The end condition</p>
          </div>
          <div class="description">
            <p>At present a human-readable string describing some condition when the
          ac tion should end. As XML develops it may be possible to add machine-processable
          semantics in this field.</p>
          </div>
        </xsd:documentation>
      </xsd:annotation>
    </xsd:attribute>
    <xsd:attribute name="units" type="unitsType">
      <xsd:annotation>
        <xsd:documentation>
          <div class="summary">Units for the time attributes</div>
        </xsd:documentation>
      </xsd:annotation>
    </xsd:attribute>
    <xsd:attribute name="count" type="countType">
      <xsd:annotation>
        <xsd:documentation>
          <div class="summary">Number of times the action should be repeated</div>
        </xsd:documentation>
      </xsd:annotation>
    </xsd:attribute>
  </xsd:attributeGroup>
  <xsd:group name="dataGroup" id="gp.dataGroup">
    <xsd:annotation>
      <xsd:documentation>
        <div class="summary">
          <p>A grouping of <tt>list</tt> and <tt>scalar</tt> elements for use by
           other schemas. Experimental.</p>
        </div>
        <div class="description">
          <p>This is to allow non-STM schemas to include a generic "data" component
           in their elements. It is messy and probably should not survive. Better
           extensibility mechanisms should be found.</p>
          <p>Use only within Schemas</p>
        </div>
      </xsd:documentation>
    </xsd:annotation>
    <xsd:choice>
      <xsd:element ref="list"/>
      <xsd:element ref="scalar"/>
    </xsd:choice>
  </xsd:group>
  <xsd:attributeGroup name="sourceGroup" id="attGp.source">
    <xsd:attribute name="source" type="xsd:anyURI" id="att.source">
      <xsd:annotation>
        <xsd:documentation>
          <div class="summary">An attribute linking to the source of the information</div>
          <div class="description">
            <p>A simple way of adding metadata to a piece of information.
           Likely to be fragile since the URI may disappear.</p>
          </div>
          <div class="example">
            <pre>
&lt;list&gt;
  &lt;definition source="foo.html#a3"&gt;An animal with four legs&lt;/definition&gt;
  &lt;definition source="http://www.foo.com/index.html"&gt;
    An animal with six legs&lt;/definition&gt;
&lt;/list&gt;

           </pre>
          </div>
        </xsd:documentation>
      </xsd:annotation>
    </xsd:attribute>
  </xsd:attributeGroup>
  <xsd:attributeGroup name="tit_id_convGroup" id="attGp.tit_id_convGroup">
    <xsd:annotation>
      <xsd:documentation>
        <div class="summary">An group of attribute applicable to most STM-ML elements</div>
        <div class="description">
          <p>A group of attribute applicable to most STM-ML elements. It is
        recommended that IDs are used widely. Titles have no semantics but
        are useful for humans (e.g. a bond angle could be labelled "ortho"
        or "gamma". Coventions are inherited by subelements; the default is the
        current schema.</p>
        </div>
      </xsd:documentation>
    </xsd:annotation>
    <xsd:attributeGroup ref="idGroup"/>
    <xsd:attributeGroup ref="titleGroup"/>
    <xsd:attributeGroup ref="convGroup"/>
  </xsd:attributeGroup>
  <xsd:attributeGroup name="tit_id_conv_dictGroup" id="attGp.tit_id_conv_dictGroup">
    <xsd:annotation>
      <xsd:documentation>
        <div class="summary">Addition of the <tt>dictRef</tt> attribute to the <tt>tit_id_conv</tt> group.</div>
      </xsd:documentation>
    </xsd:annotation>
    <xsd:attributeGroup ref="tit_id_convGroup"/>
    <xsd:attributeGroup ref="dictRefGroup"/>
  </xsd:attributeGroup>
  <xsd:attribute name="foo" type="xsd:string" id="att.foo345"/>
</xsd:schema>