<!-- Converted to DocBook/SGML by Kevin Conder -->
<section id="OrchExpress">
  <title>Expressions</title>

  <para>
    Expressions may be composed to any depth. Each part of an expression is evaluated at its own proper rate. For instance, if the terms within a sub-expression all change at the control rate or slower, the sub-expression will be evaluated only at the control rate; that result might then be used in an audio-rate evaluation. For example, in
    <informalexample>
      <programlisting>
k1 + <emphasis>abs</emphasis>(<emphasis>int</emphasis>(p5) + <emphasis>frac</emphasis>(p5) * 100/12 + <emphasis>sqrt</emphasis>(k1))
      </programlisting>
    </informalexample>
  </para>

  <para>
    the 100/12 would be evaluated at orch init, the p5 expressions evaluated at note i-time, and the remainder of the expression evaluated every k-period. The whole might occur in a unit generator argument position, or be part of an assignment statement.
  </para>
</section>
