and_permutations">Combinations_and_permutations</a></p>
<pre><code class="nim hljs"><span class="hljs-keyword">proc</span> perm(n, k: <span class="hljs-built_in">int32</span>): <span class="hljs-type">BigInt</span> =
  <span class="hljs-literal">result</span> = initBigInt <span class="hljs-number">1</span>      <span class="hljs-comment">## I could also use `one` (a const)</span>
  <span class="hljs-keyword">var</span>
    k = n - k
    n = n
  <span class="hljs-keyword">while</span> n &gt; k:
    <span cla