title: Finding if two strings are equal structurally using scheme
body: <p>Write a Scheme predicate function that tests for the structural equality of two given lists. Two lists are structurally equal if they have the same list structure, although their atoms may be different.</p>
  
  <p>(123) (456) is ok
  (1(23))((12)3) is not ok</p>
  
  <p>I have no idea how to do this. Any help would be appreciated.</p>