title: What is the meaning of this snippet of code?
body: <p>I am studying Scala language and I do not understand this piece of code:</p>
  <pre class="lang-scala prettyprint-override"><code>for {
    i &lt;- Set(2,3)
    j &lt;- 1 to i
    k &lt;- i to 2 by -1
  } yield (j,k)
  </code></pre>
  <p>What does it mean that <code>j</code> is a Range from <code>1 to i</code> when <code>i</code> is a <code>Set</code>?</p>