title: How do you halt in DrScheme's implementation of R5RS?
body: <p>When using DrScheme with R5RS, there is no error function. I plan to write my own, but can't figure out how to halt the program execution. I tried commands such as:</p>
  
  <ul>
  <li>(halt) </li>
  <li>(exit) </li>
  <li>(error)</li>
  </ul>
  
  <p>and none worked. How do you halt program execution?</p>