title: Infix to Prefix conversion scheme
body: <p>I'm trying to figure out how to convert an infix expression to prefix in Scheme. </p>
  
  <p>I found <a href="https://stackoverflow.com/questions/15931996/calculating-and-converting-prefix-to-infix">this</a> post which does what I want but in the opposite direction. What changes when going from infix->prefix instead of prefix->infix?</p>
  
  <p>Edit: I forgot to mention I need to account and handle for variables. For example the input </p>
  
  <p><code>'(2 + 3 * a ^ 5 + b)</code></p>