title: How do you undo setting an option in vim?
body: <p>I often call</p>
  
  <pre><code>:set spell
  </code></pre>
  
  <p>only to immediately call</p>
  
  <pre><code>:set nospell
  </code></pre>
  
  <p>once I've corrected the word I was unsure of.</p>
  
  <p>I can make this faster by mapping both commands, but I'm looking for a more general way to speed this up. Is it possible to undo the last option :set?</p>