title: How can the Ctrl+0 through Ctrl+9 key bindings be mapped in Vim?
body: <p>Why can’t I map—using any of the <code>*map</code> commands (<code>nmap</code>, <code>imap</code>, etc.)—the <kbd>Ctrl</kbd>+<kbd>0</kbd> through <kbd>Ctrl</kbd>+<kbd>9</kbd> key strokes? In fact, it appears that some of them, like <kbd>Ctrl</kbd>+<kbd>3</kbd>, are bound to <code>^[</code> at the X Window level. How can I make Vim override those default bindings?</p>
  <p>That is, if I do <code>imap &lt;C-3&gt; fancystuffhere</code>, typing <kbd>Ctrl</kbd>+<kbd>3</kbd> in Insert mode puts me into Normal mode, instead of inserting 'fancystuffhere'.</p>
  <p>I’m using X11 on Linux.</p>