title: What does an arrow pointing upwards mean in pseudocode?
body: <p>I am encountering an <em>up-arrow</em> in pseudocode examples of balanced binary search trees. What is the author intending to denote by the use of such a symbol which can either follow or precede a variable?</p>
  
  <pre><code>type data = ....;
    Tree = ↑node;
    node = record
      left, right: Tree;
      level: integer;
      key: data;
    end;
  var bottom, deleted, last: Tree;
  
  procedure InitGlobalVariables;
  begin
    new (bottom);
    bottom↑.level := 0;
    bottom↑.left := bottom;
    bottom↑.right := bottom;
    deleted := bottom;
  end;
  </code></pre>
  
  <p>This pseudocode is a reference to building Red-Black-Trees found <a href="http://user.it.uu.se/~arnea/ps/simp.pdf" rel="nofollow">here</a> written by Arne Andersson.</p>