title: Variables infix to prefix to postfix
body: <p>I searched all over the internet for a good implementation in converting not numbers expressions but variable expressions from infix notation into prefix and postfix. All the searches I did weren't successful. Basically I want to see if there is any implementation yet in PHP so I could modify it to support more operators not only the (-,*,+,=). </p>
  
  <p>For example convert:</p>
  
  <pre><code>a+b/c*(p/c)
  </code></pre>
  
  <p>While keeping the variable names, and not having to enter numbers to evaluate them.</p>