title: How to unmap a insert-key on vim?
body: <p>On <code>vim</code>, <em>command-mode</em> keys can be mapped through the <code>ex</code> command <code>:map &lt;key&gt; &lt;macro&gt;</code> and <em>insert-mode</em> keys can be mapped through <code>:map! &lt;key&gt; &lt;macro&gt;</code>. After mapped, the commands to remove the mapping from the <em>command-mode</em> keys and <em>insert-mode</em> keys are <code>unmap &lt;key&gt;</code> and <code>unmap! &lt;key&gt;</code> respectively.</p>
  
  <p>This works well with <em>command-mode</em> keys, but with <em>insert-mode</em> keys the key expansion also works on the <code>ex</code> command line prompt: trying to type the key end up in the macro expansion taking place resulting in bad argument to the <code>unmap!</code> command (<code>E474: Invalid Argument</code>) or maybe the command might try to unmap some different key from the one intended (<code>E31: No such mapping</code>).</p>
  
  <p>How can someone correctly remove a <em>insert-mode</em> mapped key on <code>vim</code>?</p>