Derivatives and Integrals: An Annotated Discourse

<exercises xml:id="exercises" label="exercises-top-level">
  <title>Exercises, Top-Level</title>
  <introduction>
    <p>
    </p>
    <p>
      This <tag>exercises</tag> of the sample article is a peer of all the preceding <tag>section</tag> and is the only such <tag>exercises</tag>.
      As such, it is not numbered, and contains only <tag>exercise</tag>,
      but for this <tag>introduction</tag> you are reading.
      The <tag>exercises</tag> contained within will be numbered in cross-references according to the enclosing division,
      in this case the entire article and so without any qualification, to wit,
      <xref ref="exercise-challenging-one-top" text="type-global" />.
    </p>
  </introduction>
  <exercise>
    <title>Drill One</title>
    <statement>
      <p>
        Lorem ipsum dolor sit amet, consectetur adipiscing elit.
        Cras congue urna nulla.
        Aliquam eget euismod tellus.
        Maecenas nibh libero, venenatis a laoreet in, tempor sit amet sem.
        Morbi sit amet justo tempor velit auctor placerat.
        Maecenas nec lobortis orci.
        Aenean dictum enim lacus, ac blandit lacus elementum nec.
        Mauris porttitor neque volutpat tincidunt sollicitudin.
        Cras porta lectus ac facilisis tempor.
        Suspendisse in velit nisl.
        Sed convallis leo at nunc aliquet fermentum.
        Pellentesque feugiat at ex sed elementum.
        In porta vulputate ipsum sit amet consectetur.
      </p>
    </statement>
  </exercise>
  <exercise>
    <title>Drill Two</title>
    <statement>
      <p>
        Aliquam sagittis ex at magna porttitor,
        quis scelerisque ligula malesuada.
        Vestibulum vitae mauris id nisi pretium ornare a id lectus.
        Nam suscipit magna id sem ultricies vestibulum.
        Nulla facilisi.
        Duis venenatis lectus massa, ac mollis nisi suscipit non.
        Sed et sapien vulputate, imperdiet nibh vel, lobortis nisl.
        Curabitur sagittis justo nibh.
        Nulla vulputate sodales justo at efficitur.
        Cras justo augue, mollis vitae nulla sed,
        vestibulum tincidunt ante.
        Vestibulum et lorem lectus.
        Maecenas accumsan lacus a nisi euismod rutrum eu dapibus justo.
        Etiam scelerisque a odio a euismod.
        Pellentesque vestibulum pellentesque nisi, a tempus erat cursus ac.
        Morbi ut auctor lectus.
      </p>
      <figure>
        <caption>Testing numbering in a <tag>exercises</tag> without a number</caption>
        <image source="images/cross-square.png" width="20%" />
      </figure>
    </statement>
  </exercise>
  <exercise>
    <title>Drill Three</title>
    <statement>
      <p>
        Nam congue ex nec justo iaculis maximus.
        Vestibulum lobortis magna sed urna auctor,
        vel dignissim massa posuere.
        In sed venenatis elit.
        Vivamus congue gravida tempus.
        Nunc quis fermentum nisi.
        Nullam hendrerit lorem et tellus semper,
        sit amet scelerisque purus lobortis.
        Quisque sollicitudin quis neque eu suscipit.
        Praesent volutpat justo quis magna vehicula molestie.
      </p>
    </statement>
  </exercise>
  <exercise xml:id="exercise-challenging-one-top">
    <title>Challenging One</title>
    <statement>
      <p>
        Lorem ipsum dolor sit amet, consectetur adipiscing elit.
        Cras congue urna nulla.
        Aliquam eget euismod tellus.
        Maecenas nibh libero, venenatis a laoreet in, tempor sit amet sem.
        Morbi sit amet justo tempor velit auctor placerat.
        Maecenas nec lobortis orci.
        Aenean dictum enim lacus, ac blandit lacus elementum nec.
        Mauris porttitor neque volutpat tincidunt sollicitudin.
        Cras porta lectus ac facilisis tempor.
        Suspendisse in velit nisl.
        Sed convallis leo at nunc aliquet fermentum.
        Pellentesque feugiat at ex sed elementum.
        In porta vulputate ipsum sit amet consectetur.
      </p>
    </statement>
  </exercise>
  <exercisegroup>
    <introduction>
      <p>
        An introduction to an <c>exercisegroup</c>.
        This is here to attempt to interrupt the flow of the counting from this division to the next.
      </p>
    </introduction>
    <exercise>
      <title>Challenging Two</title>
      <statement>
        <p>
          Aliquam sagittis ex at magna porttitor,
          quis scelerisque ligula malesuada.
          Vestibulum vitae mauris id nisi pretium ornare a id lectus.
          Nam suscipit magna id sem ultricies vestibulum.
          Nulla facilisi.
          Duis venenatis lectus massa, ac mollis nisi suscipit non.
          Sed et sapien vulputate, imperdiet nibh vel, lobortis nisl.
          Curabitur sagittis justo nibh.
        </p>
        <p>
          Nulla vulputate sodales justo at efficitur.
          Cras justo augue, mollis vitae nulla sed,
          vestibulum tincidunt ante.
          Vestibulum et lorem lectus.
          Maecenas accumsan lacus a nisi euismod rutrum eu dapibus justo.
          Etiam scelerisque a odio a euismod.
          Pellentesque vestibulum pellentesque nisi, a tempus erat cursus ac.
          Morbi ut auctor lectus.
        </p>
      </statement>
    </exercise>
    <exercise>
      <title>Challenging Three</title>
      <statement>
        <p>
          Nam congue ex nec justo iaculis maximus.
          Vestibulum lobortis magna sed urna auctor,
          vel dignissim massa posuere.
          In sed venenatis elit.
          Vivamus congue gravida tempus.
          Nunc quis fermentum nisi.
          Nullam hendrerit lorem et tellus semper,
          sit amet scelerisque purus lobortis.
          Quisque sollicitudin quis neque eu suscipit.
          Praesent volutpat justo quis magna vehicula molestie.
        </p>
      </statement>
    </exercise>
  </exercisegroup>
  <exercise>
    <title>Impossible One</title>
    <statement>
      <p>
        Lorem ipsum dolor sit amet, consectetur adipiscing elit.
        Cras congue urna nulla.
        Aliquam eget euismod tellus.
        Maecenas nibh libero, venenatis a laoreet in, tempor sit amet sem.
        Morbi sit amet justo tempor velit auctor placerat.
        Maecenas nec lobortis orci.
        Aenean dictum enim lacus, ac blandit lacus elementum nec.
        Mauris porttitor neque volutpat tincidunt sollicitudin.
        Cras porta lectus ac facilisis tempor.
        Suspendisse in velit nisl.
        Sed convallis leo at nunc aliquet fermentum.
        Pellentesque feugiat at ex sed elementum.
        In porta vulputate ipsum sit amet consectetur.
      </p>
    </statement>
  </exercise>
  <exercise>
    <title>Impossible Two</title>
    <statement>
      <p>
        Aliquam sagittis ex at magna porttitor,
        quis scelerisque ligula malesuada.
        Vestibulum vitae mauris id nisi pretium ornare a id lectus.
        Nam suscipit magna id sem ultricies vestibulum.
        Nulla facilisi.
        Duis venenatis lectus massa, ac mollis nisi suscipit non.
        Sed et sapien vulputate, imperdiet nibh vel, lobortis nisl.
        Curabitur sagittis justo nibh.
        Nulla vulputate sodales justo at efficitur.
        Cras justo augue, mollis vitae nulla sed,
        vestibulum tincidunt ante.
        Vestibulum et lorem lectus.
        Maecenas accumsan lacus a nisi euismod rutrum eu dapibus justo.
        Etiam scelerisque a odio a euismod.
        Pellentesque vestibulum pellentesque nisi, a tempus erat cursus ac.
        Morbi ut auctor lectus.
      </p>
    </statement>
  </exercise>
  <exercise>
    <title>Impossible Three</title>
    <statement>
      <p>
        Nam congue ex nec justo iaculis maximus.
        Vestibulum lobortis magna sed urna auctor,
        vel dignissim massa posuere.
        In sed venenatis elit.
        Vivamus congue gravida tempus.
        Nunc quis fermentum nisi.
        Nullam hendrerit lorem et tellus semper,
        sit amet scelerisque purus lobortis.
        Quisque sollicitudin quis neque eu suscipit.
        Praesent volutpat justo quis magna vehicula molestie.
      </p>
    </statement>
  </exercise>
  <exercise>
    <title>An Exercise in a Section</title>
    <statement>
      <p>
        Exercises can appear in a
        <q>section</q>
        of their own.
        You need to give the section a title,
        even if it seems obvious what to call it.
        Individual exercises may have titles, as you choose.
        Problem: How should we hide solutions?
      </p>
    </statement>
    <solution>
      <p>
        Maybe a global switch should be used to suppress solutions,
        while a separate processing regime could use them as part of a solutions manual.
      </p>
    </solution>
  </exercise>
  <exercise number="42a" xml:id="exercise-with-hardcoded-number">
    <title>An Exercise with a Hard-Coded Problem Number</title>
    <statement>
      <p>
        Compute the definite integral <m>\definiteintegral{2}{4}{x^2}{x}</m>,
        not as an approximate value from a Riemann sum,
        but as an exact value based of the limit by using the Fundamental Theorem.
      </p>
    </statement>
    <solution xml:id="solution-antiderivative">
      <p>
        An antiderivative of <m>x^2</m> is <m>F(x)=x^3/3</m>, so by the FTC,
        <me>
          \definiteintegral{2}{4}{x^2}{x}=F(4)-F(2)=\frac{1}{3}\left(4^3-2^3\right)=\frac{56}{3}
        </me>!?!
        This is indeed an exciting result,
        but we are mostly interested in seeing that the sentence-ending punctuation is absorbed properly into the displayed equation.
      </p>
    </solution>
  </exercise>
  <exercise>
    <statement>
      <p>
        Can you prove Corollary<nbsp /><xref ref="corollary-FTC-derivative" /> directly?
        If not consider that a problem could have several parts,
        which should be formatted as a second-level list,
        since the problems normally get numbered at the top level.
        <ol>
          <li>
            <p>
              Why is this result a Corollary?
            </p>
          </li>
          <li>
            <p>
              Could you interchange the Theorem and Corollary?
            </p>
          </li>
        </ol>
      </p>
    </statement>

    <hint>
      <title>MVT</title>
      <p>
        Consider the definite integral as an area function and employ the Mean Value Theorem.
      </p>
    </hint>

    <hint xml:id="exercise-complicated-second-hint">
      <title>Motivator</title>
      <p>
        Think harder!
      </p>
    </hint>

    <answer xml:id="exercise-complicated-first-answer">
      <title>Helpful</title>
      <p>
        <ol>
          <li>
            <p>
              It follows easily.
            </p>
          </li>
          <li>
            <p>
              Yes.
            </p>
          </li>
        </ol>
      </p>
    </answer>

    <solution>
      <p>
        We could prove either result first,
        then obtain the other as an easy consequence.
      </p>
    </solution>
  </exercise>
</exercises>