te the lowest numeric value greater than x.
      </p>
<p>
        Let <span class="bold"><strong><code class="computeroutput"><span class="identifier">prev</span><span class="special">(</span><span class="identifier">x</span><span class="special">)</span></code></strong></span>
        denote the highest numeric value lower then x.
      </p>
<p>
        Let <span class="bold"><strong><code class="computeroutput"><span class="identifier">v</span><span class="special">=</span><span class="identifier">prev</