title: TCL: check if variable is list
body: <pre><code>set var1 A
  
  set var2 {A}
  </code></pre>
  
  <p>Is it possible to check if variable is list in TCL? For <code>var1</code> and <code>var2</code> <code>llength</code> gives <code>1</code>. I am thinking that these 2 variables are considered same. They are both lists with 1 element. Am I right?</p>