elements return <code class="code">-1</code> since <code class="code">lnot (-1) = 0</code>
  if <code class="code">key</code> is larger than all elements return <code class="code">- (len + 1)</code> since <code class="code">lnot (-(len+1)) = len</code><br>
 
                    </div>
                     <div class="examples">
                    <pre class="example"> <pre class="codepre"><code class="code">     binarySearchBy [|1;2;3;4;33;35;36|] 33 = 4;;
     lnot (binarySearchBy [|1;3;5;7|] 4) = 2;;
   