title: Use CrossHair to distinguish between automata and python function
body: <p>I have a function which defines a language, let's call L, this function gets a word and returns True or False.</p>
  <p>I have also a deterministic finite autumata which suppose to accept words that are in the language and regret words that are not in the language L.</p>
  <p>My mission is to get a counterexample that will distinguish between the dfa and the python function.</p>
  <p>I wonder if CrossHair can be useful for this task.</p>
  <p>I expect for something like:</p>
  <pre><code>counterexmaple = checker(dfa, func)
  </code></pre>
  <p>Thanks</p>