anchor.diff:    (ceasar-encrypt str (- 0 shift)))
   
   (ceasar-encrypt (ceasar-encrypt "ab c" 28) -28)
  -
   
   (defun transposition-encrypt (msg key)
     "Transpose characters in msg by size of key"
  
positive.code: (defun reverse-cypher (msg)
    (reverse msg))
  
  (reverse-cypher "123")
  
  (defconstant +letters+ "abcdefghijklmnopqrstuvwxyz")
  
  (defun get-char-with-shift (c shift)
  
negative.code:     (loop for c across src do (vector-push c array)) array))
  
  (transposition-encrypt "Common sense is not so common." 8)
  