title: Represent "less-than" symbol in Sublime Text regex in syntax definition
body: <p>I'm working with an ancient pre-XML markup that uses codes of the form "$=x", where x may be an alphabetic character or a symbol on the keyboard, such as <code>;</code> (semicolon), <code>?</code> (question mark), or <code>&lt;</code> (<strike>right</strike> left angle bracket, aka <strike>greater-than</strike> less-than). [Note after editing: the confusion manifested in the question as originally phrased goes to the heart of the problem. See my comment to the accepted answer. RS]</p>
  
  <p>So I've modified a copy of XML.tmLanguage syntax definition file in my User folder to identify the eleven different categories that these codes represent, so I can easily see them in the large text files (which also contain XML markup) I'm working with.</p>
  
  <p>For all the symbols except <code>&lt;</code> I'm able to escape the symbol by preceding it with a backslash. But in the Boost regex engine that ST2 uses, <code>\&lt;</code> is how you indicate that you want to match only at the start of a word. Consequently I've been unable to get this code to be properly recognized and highlighted.</p>
  
  <p>I've looked everywhere for how to escape the <code>&lt;</code> symbol in this circumstance. I've tried preceding it with 0, 1, 2, 3 and 4 back-slashes; and I also tried using the hexadecimal escape code <code>\x{3009}</code>. [Note: this is the code for greater-than instead of less-than.]</p>
  
  <p>All in vain. (A few alternatives didn't generate an error message but also didn't highlight the code.)</p>
  
  <p>Because the codes I'm working with need to be colored differently, I can't use a generic symbol in lieu of <code>&lt;</code>, and I can't specify it either. How do I get this?</p>