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  <front>
    <journal-meta>
      <journal-id journal-id-type="publisher-id">109</journal-id>
      <journal-id journal-id-type="index">urn:lsid:arphahub.com:pub:3dc5f44e-8666-58db-bc76-a455210e8891</journal-id>
      <journal-title-group>
        <journal-title xml:lang="en">JUCS - Journal of Universal Computer Science</journal-title>
        <abbrev-journal-title xml:lang="en">jucs</abbrev-journal-title>
      </journal-title-group>
      <issn pub-type="ppub">0948-695X</issn>
      <issn pub-type="epub">0948-6968</issn>
      <publisher>
        <publisher-name>Journal of Universal Computer Science</publisher-name>
      </publisher>
    </journal-meta>
    <article-meta>
      <article-id pub-id-type="doi">10.3217/jucs-004-06-0574</article-id>
      <article-id pub-id-type="publisher-id">27500</article-id>
      <article-categories>
        <subj-group subj-group-type="heading">
          <subject>Research Article</subject>
        </subj-group>
        <subj-group subj-group-type="scientific_subject">
          <subject>F.1.3 - Complexity Measures and Classes</subject>
        </subj-group>
      </article-categories>
      <title-group>
        <article-title>Query Order and the Polynomial Hierarchy</article-title>
      </title-group>
      <contrib-group content-type="authors">
        <contrib contrib-type="author" corresp="yes">
          <name name-style="western">
            <surname>Hemaspaandra</surname>
            <given-names>Edith</given-names>
          </name>
          <email xlink:type="simple">edith@bamboo.lemoyne.edu</email>
          <xref ref-type="aff" rid="A1">1</xref>
        </contrib>
        <contrib contrib-type="author" corresp="no">
          <name name-style="western">
            <surname>Hemaspaandra</surname>
            <given-names>Lane A.</given-names>
          </name>
          <xref ref-type="aff" rid="A2">2</xref>
        </contrib>
        <contrib contrib-type="author" corresp="no">
          <name name-style="western">
            <surname>Hempel</surname>
            <given-names>Harald</given-names>
          </name>
          <xref ref-type="aff" rid="A3">3</xref>
        </contrib>
      </contrib-group>
      <aff id="A1">
        <label>1</label>
        <addr-line content-type="verbatim">Department of Mathematics, Le Moyne College, Syracuse, United States of America</addr-line>
        <institution>Department of Mathematics, Le Moyne College</institution>
        <addr-line content-type="city">Syracuse</addr-line>
        <country>United States of America</country>
      </aff>
      <aff id="A2">
        <label>2</label>
        <addr-line content-type="verbatim">Department of Computer Science, University of Rochester, Rochester, NY, United States of America</addr-line>
        <institution>Department of Computer Science, University of Rochester</institution>
        <addr-line content-type="city">Rochester, NY</addr-line>
        <country>United States of America</country>
      </aff>
      <aff id="A3">
        <label>3</label>
        <addr-line content-type="verbatim">Institut für Informatik, Friedrich-Schiller-Universität Jena, , Germany</addr-line>
        <institution>Institut für Informatik, Friedrich-Schiller-Universität Jena</institution>
        <country>Germany</country>
      </aff>
      <author-notes>
        <fn fn-type="corresp">
          <p>Corresponding author: Edith Hemaspaandra (<email xlink:type="simple">edith@bamboo.lemoyne.edu</email>).</p>
        </fn>
        <fn fn-type="edited-by">
          <p>Academic editor: </p>
        </fn>
      </author-notes>
      <pub-date pub-type="collection">
        <year>1998</year>
      </pub-date>
      <pub-date pub-type="epub">
        <day>28</day>
        <month>06</month>
        <year>1998</year>
      </pub-date>
      <volume>4</volume>
      <issue>6</issue>
      <fpage>574</fpage>
      <lpage>588</lpage>
      <uri content-type="arpha" xlink:href="http://openbiodiv.net/158A36DC-7C43-54D9-8752-55F520A1860D">158A36DC-7C43-54D9-8752-55F520A1860D</uri>
      <uri content-type="zenodo_dep_id" xlink:href="https://zenodo.org/record/6995576">6995576</uri>
      <permissions>
        <copyright-statement>Edith Hemaspaandra, Lane A. Hemaspaandra, Harald Hempel</copyright-statement>
        <license license-type="creative-commons-attribution" xlink:href="" xlink:type="simple">
          <license-p>This article is freely available under the J.UCS Open Content License.</license-p>
        </license>
      </permissions>
      <abstract>
        <label>Abstract</label>
        <p>Hemaspaandra, Hempel, and Wechsung [HHW] initiated the field of query order, which studies the ways in which computational power is affected by the order in which information sources are accessed. The present paper studies, for the first time, query order as it applies to the levels of the polynomial hierarchy.  denotes the class of languages computable by a polynomial-time machine that is allowed one query to  followed by one query to  [HHW]. We prove that the levels of the polynomial hierarchy are order-oblivious:  Yet, we also show that these ordered query classes form new levels in the polynomial hierarchy unless the polynomial hierarchy collapses. We prove that all leaf language classes - and thus essentially all standard complexity classes - inherit all order-obliviousness results that hold for P.</p>
      </abstract>
    </article-meta>
  </front>
</article>
