code: def _cvc(self, word, i):
          
          if i == 0: return False  # i == 0 never happens perhaps
          if i == 1: return (not self._cons(word, 0) and self._cons(word, 1))
          if not self._cons(word, i) or self._cons(word, i-1) or not self._cons(word, i-2): return False
  
          ch = word[i]
          if ch == 'w' or ch == 'x' or ch == 'y':
              return False
  
          return True
docs: cvc(i) is TRUE <=>
  
          a) ( --NEW--) i == 1, and word[0] word[1] is vowel consonant, or
  
          b) word[i - 2], word[i - 1], word[i] has the form consonant -
             vowel - consonant and also if the second c is not w, x or y. this
             is used when trying to restore an e at the end of a short word.
             e.g.
  
                 cav(e), lov(e), hop(e), crim(e), but
                 snow, box, tray.