title: Importing clojure.contrib.generic.math-functions
body: <p>I download the clojure 1.2 and clojure-contrib-1.2.0.jar from the <a href="http://clojure.org/downloads" rel="nofollow noreferrer">download site</a>.</p>
  
  <p>And I found the info about the <a href="http://richhickey.github.com/clojure-contrib/generic.math-functions-api.html#clojure.contrib.generic.math-functions/sqrt" rel="nofollow noreferrer">math functions</a>.</p>
  
  <p>As is shown in the example, I tried to run the code.</p>
  
  <pre><code>(ns your-namespace
    (:require clojure.contrib.generic.math-functions))
  (println (abs 10))
  </code></pre>
  
  <p>But, I got the following error, when I run as follows.</p>
  
  <pre><code>CLOJURE_JAR=/Users/smcho/bin/jar/clojure.jar:/Users/smcho/bin/jar/clojure-contrib-1.2.0.jar
  java -cp $CLOJURE_JAR:$CLASSPATH clojure.main SOURCE.CLJ
  </code></pre>
  
  <pre>
  Exception in thread "main" java.lang.Exception: Unable to resolve symbol: abs in this context (hello.clj:4)
      at clojure.lang.Compiler.analyze(Compiler.java:5205)
          ...
      at clojure.main.main(main.java:37)
  Caused by: java.lang.Exception: Unable to resolve symbol: abs in this context
      at clojure.lang.Compiler.resolveIn(Compiler.java:5677)
      at clojure.lang.Compiler.resolve(Compiler.java:5621)
      at clojure.lang.Compiler.analyzeSymbol(Compiler.java:5584)
      at clojure.lang.Compiler.analyze(Compiler.java:5172)
      ... 25 more
  </pre>
  
  <p>What might be wrong?</p>