title: When are sets evaluated for unique elements?
body: <p>At what point is a set evaluated for unique elements. For each:</p>
  
  <pre><code>(def set1 #{1, 2, 3, 3})
  (def set2 #{1, 2, 3, (+ 1 2)})
  
  (defn foo 
  [a b]
  #{1, 2, a, b})
  
  (foo 3 (+ 1 2))
  </code></pre>
  
  <p>Is it a combination of compile time and run-time or something else?</p>