title: Simplification of REGEX expression
body: <p>I need to prove or disprove the below REGEX</p>
  
  <pre><code>(RS + R )* R = R (SR + R)*
  // or, for programmers:
  /(RS|R)*R/ == /R(SR|R)*/
  </code></pre>
  
  <p>I have a strong gut feel that they are equivalent, but how do i give a step by step proof using the laws of REGEX.</p>