title: filter unbound in chicken scheme. Why?
body: <p>I'm starting out with chicken scheme. The code below works in the mit-scheme repl but doesn't with csi. csi has filter defined in the docs but I get an unbound variable error when I run the code below. </p>
  
  <pre><code>    CHICKEN
  (c) 2008-2015, The CHICKEN Team
  (c) 2000-2007, Felix L. Winkelmann
  Version 4.10.0 (rev b259631)
  macosx-unix-clang-x86-64 [ 64bit manyargs dload ptables ]
  compiled 2015-08-04 on yves.more-magic.net (Linux)
  
  #;1&gt; (filter odd? '(1 2 3 ))
  
  Error: unbound variable: filter
  
      Call history:
  
      &lt;syntax&gt;          (filter odd? (quote (1 2 3)))
      &lt;syntax&gt;          (quote (1 2 3))
      &lt;syntax&gt;          (##core#quote (1 2 3))
      &lt;eval&gt;    (filter odd? (quote (1 2 3))) &lt;--
  #;1&gt;
  </code></pre>