title: escape backslash in ANTLR
body: <p>How can I make this "/\" show up in my interpreter tree? </p>
  
  <pre><code>expression
      :   boolean_expression (('/\'' | '\'/') boolean_expression)* 
      ;
  </code></pre>
  
  <p>I already managed to fix \/ by putting '\'/' as you can see. and it prints \/
  but /\ wont work. </p>
  
  <p>Before you ask, this is a project and I must use these notations.</p>