<xsd:complexType name="CalculationFromObservation" abstract="true" >
  <xsd:annotation>
    <xsd:documentation xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en">Abstract base class for all calculation from observed values</xsd:documentation>
  </xsd:annotation>
  <xsd:sequence>
    <xsd:choice>
      <xsd:element name="initialLevel" type="xsd:decimal">
        <xsd:annotation>
          <xsd:documentation xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en">Contract will strike off this initial level</xsd:documentation>
        </xsd:annotation>
      </xsd:element>
      <xsd:element name="closingLevel" type="xsd:boolean">
        <xsd:annotation>
          <xsd:documentation xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en">If true this contract will strike off the closing level of the default exchange traded contract</xsd:documentation>
        </xsd:annotation>
      </xsd:element>
      <xsd:element name="expiringLevel" type="xsd:boolean">
        <xsd:annotation>
          <xsd:documentation xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en">If true this contract will strike off the expiring level of the default exchange traded contract</xsd:documentation>
        </xsd:annotation>
      </xsd:element>
    </xsd:choice>
    <xsd:element minOccurs="0" name="expectedN" type="xsd:positiveInteger">
      <xsd:annotation>
        <xsd:documentation xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en">Expected number of trading days</xsd:documentation>
      </xsd:annotation>
    </xsd:element>
  </xsd:sequence>
</xsd:complexType>