Derivatives and Integrals: An Annotated Discourse

<exercises label="exercises-structured">
  <title>Exercise Section, Structured</title>
  <introduction>
    <p>
      A collection of exercises,
      in a top-level <tag>exercises</tag> division,
      structured with <tag>subexercises</tag>.
    </p>
  </introduction>
  <subexercises>
  <title>Easy Exercises</title>
  <exercise>
    <title>Arithmetic</title>
    <statement>
      <p>
        Compute <m>3+4</m>.
      </p>
    </statement>
    <answer>
      <p>
        <m>7</m>
      </p>
    </answer>
  </exercise>
  <exercise>
    <title>Trigonometry</title>
    <statement>
      <p>
        Compute <m>\sin(\pi/4)</m>.
      </p>
    </statement>
  </exercise>
  </subexercises>
  <subexercises xml:id="hard-subexercises">
  <title>Hard Problems</title>
  <exercise>
    <title>Number Theory</title>
    <statement>
      <p>
        Prove Fermat's Last Theorem.
      </p>
    </statement>
  </exercise>
  <exercise>
    <title>Millenial</title>
    <statement>
      <p>
        Find general solutions to the Navier-Stokes equation.
      </p>
    </statement>
  </exercise>
  </subexercises>
  <subexercises>
  <title>With an Exercise Group</title>
  <exercisegroup>
    <introduction>
      <p>
        This is an exercise group, and this is its introduction.
      </p>
    </introduction>
    <exercise>
      <title>One</title>
      <statement>
        <p>
          <m>6-5</m>
        </p>
      </statement>
      <hint>
        <p>
          Subtract.
        </p>
      </hint>
    </exercise>
    <exercise>
      <title>Two</title>
      <statement>
        <p>
          <m>1+1</m>
        </p>
      </statement>
    </exercise>
  </exercisegroup>
  <exercise>
    <title>Outside exercisegroup, inside subexercises</title>
    <statement>
      <p>
        6+5
      </p>
    </statement>
  </exercise>
  </subexercises>
</exercises>