anchor.diff:      "setf is used to assign values to symbols.  These symbols may refer to
        variables with lexical or dynamic scope."
     (setf my-name "David")
  -  (assert-equal my-name ____)
  +  (assert-equal my-name "David")
     " In SBCL, if the symbol isn't defined as a variable, via a top-level defvar
     or let statement, the setf call may result in a warning."
     (setf my-clones-name my-name)
  -  (assert-equal "David" ____)
  +  (assert-equal "David" my-clones-name)
     (setf a 5)
     (setf b 10)
  -  (setf c ___)
  +  (setf c 50)
     (assert-equal 50 c))
   
   
  
positive.code:      lexical form.  After which, the previous value, if it exists, is visible again."
    (setf a 10)
    (setf b 20)
    (assert-equal a ___)
    (assert-equal b ___)
    (let ((a 1111)
          (b 2222))
      (assert-equal a ___)
      (assert-equal b ___))
    (assert-equal a ___)
    (assert-equal b ___))
  
  
  (define-test test-let-default-value
      "let vars have a default value"
      (let ((x))
        (assert-equal ___ x)))
  
  (define-test test-let-bindings-are-parallel
      "When defining the bindings in the let form, later bindings may not depend
  
negative.code:         (cond ((> a 0) :positive)
                ((< a 0) :negative)
                (t :zero)))
    (assert-equal :positive c))
  
  
  (defun cartoon-dads (input)
    " you should be able to complete this cond statement"
    (cond ((equal input :bart) :homer)
  		((equal input :stewie) :peter)
  		((equal input :stan) :randy)
          (t :unknown)))
  
  (define-test test-your-own-cond-statement
  