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Taxonomy based on XBRL standard Version 2.1.
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    <appinfo>
      <link:roleType
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        <link:definition>101000 - Document - Document Information</link:definition>
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        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType
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        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType
        roleURI="http://www.qqq.com/role/ClassesOfPreferredStock"
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        <link:definition>104001 - Schedule - Classes of Preferred Stock</link:definition>
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        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType
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        <link:definition>104003 - Schedule - Classes of Treasury Stock</link:definition>
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        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType
        roleURI="http://www.qqq.com/role/OtherParenthetical"
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        <link:definition>104004 - Schedule - Other Parenthetical</link:definition>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType
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        <link:usedOn>link:presentationLink</link:usedOn>
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        <link:usedOn>link:definitionLink</link:usedOn>
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        <link:usedOn>link:definitionLink</link:usedOn>
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      <link:roleType
        roleURI="http://www.qqq.com/role/PropertyPlantAndEquipmentDetail"
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        <link:definition>305000 - Disclosure - Note D. Property, Plant and Equipment Detail</link:definition>
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        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType
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        <link:definition>306000 - Disclosure - Note E. Maturities of Long-term Debt</link:definition>
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        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
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      <link:roleType
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        <link:definition>306010 - Disclosure - Note F. Long-term Debt Instruments</link:definition>
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      <link:roleType
        roleURI="http://www.qqq.com/role/Commitments"
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        <link:definition>306020 - Disclosure - Note G. Part 1. Commitments</link:definition>
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        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
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      <link:roleType
        roleURI="http://www.qqq.com/role/Contingencies"
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        <link:definition>306030 - Disclosure - Note G. Part 2. Contingencies</link:definition>
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        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType
        roleURI="http://www.qqq.com/role/LossContingencyAccrual"
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        <link:definition>307000 - Disclosure - Note G. Part 3. Loss Contingency Accrual</link:definition>
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        <link:usedOn>link:presentationLink</link:usedOn>
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      </link:roleType>
      <link:roleType
        roleURI="http://www.qqq.com/role/NonmonetaryTransactions"
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        <link:definition>309000 - Disclosure - Note H. Nonmonetary Transactions</link:definition>
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