lways be entered because 
the input parameter <tt>length</tt> will be greater than zero in all calls to this 
function. You can teach the analyzer facts about your code as well as document 
it by using assertions. By adding <tt>assert(length > 0)</tt> in the beginning 
of the function, you tell the analyzer that your code is never expecting a zero 
or a negative value, so it won't need to test the correctness of those paths.
</p>

<pre class="code_example">
int foo(int length) {
  int x = 0;
  <span class="