Problem in mathml2 schema layout.xsd

According to http://www.w3.org/TR/MathML2/chapter3.html#presm.menclose,
(section 3.3.9.2 Attributes)
The notation attribute should allow a list of any allowed values. "Any
number of values can be given for notation separated by whitespace; all
of those given and understood by a MathML renderer should be rendered.
For example, notation="circle horizontalstrike" should result in circle
around the contents of menclose with a horizontal line through the
contents."

However, the way notation is defined in layout.xsd, only one value is
allowed. We discovered the problem when building an expression from
MathType and parsing it against the schema. here's a snippet that
generated the error:

    <m:math>
        <m:mrow>
            <m:mrow>
                <m:menclose notation="top left">
                    <m:mrow>
                        <m:mi>a</m:mi>
                    </m:mrow>
                </m:menclose>
            </m:mrow>
        </m:mrow>
    </m:math>

Original from
http://www.w3.org/Math/XMLSchema/mathml2/presentation/layout.xsd

I've replaced the menclose declaration in my working copy of layout.xsd
with the snippet below, and don't get validation errors. However, would
we run into problems when applications using the published schema take
our xml? What would you suggest we do?

<!-- "menclose" repaired to allow multiple values in the notation
attribute -->
<xs:simpleType name="notation_attributes">
  <xs:restriction base="xs:string">
    <xs:enumeration value="actuarial" /> 
    <xs:enumeration value="longdiv" /> 
    <xs:enumeration value="radical" /> 
    <xs:enumeration value="box" /> 
    <xs:enumeration value="roundedbox" /> 
    <xs:enumeration value="circle" /> 
    <xs:enumeration value="left" /> 
    <xs:enumeration value="right" /> 
    <xs:enumeration value="top" /> 
    <xs:enumeration value="bottom" /> 
    <xs:enumeration value="updiagonalstrike" /> 
    <xs:enumeration value="downdiagonalstrike" /> 
    <xs:enumeration value="verticalstrike" /> 
    <xs:enumeration value="horizontalstrike" /> 
  </xs:restriction>
</xs:simpleType>
<xs:attributeGroup name="menclose.attlist">
  <xs:attribute name="notation" default="longdiv">
    <xs:simpleType>
      <xs:list itemType="notation_attributes"/>
    </xs:simpleType>
  </xs:attribute>
  <xs:attributeGroup ref="Common.attrib" /> 
</xs:attributeGroup>

<xs:complexType name="menclose.type">
  <xs:group ref="Presentation-expr.class" minOccurs="0"
maxOccurs="unbounded" /> 
  <xs:attributeGroup ref="menclose.attlist" /> 
</xs:complexType>

<xs:element name="menclose" type="menclose.type" /> 

Regina Hoag
Regina Hoag
SR&T Development - Assessment Technologies
Mail Stop 75-D
609-734-5204



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