anchor.diff:  
   (defun tms-values (time-multiseries positions)
     "This function returns a list of the values in a time series or multiseries
  -  at the specified positions.  A time multiseries is represented as a list of
  -  arrays with identical dimensions, where each array represents a single time
  -  step's entire data.  A time series is represented as a list.  The first value
  -  in each position is the time position."
  +at the specified positions.  A time multiseries is represented as a list of
  +arrays with identical dimensions, where each array represents a single time
  +step's entire data.  A time series is represented as a list.  The first value
  +in each position is the time position."
     (assert (listp positions))
     (setf positions (mapcar #'(lambda (position)
                                 (if (listp position)
  
positive.code: 
  (defmethod best ((list list) predicate &key (key #'identity))
    "This returns the ``best'' element in a list.  This is equivalent to, but
    faster than (O(n) vs. O(n*lg(n))), taking the first element after sorting the
    sequence with the same predicate and key."
    (when (null list)
      (return-from best nil))
    (let ((best (first list)))
  
negative.code: 
  (defun conjoin (predicate &rest predicates)
    "This function takes in one or more predicates, and returns a predicate that
  returns true whenever all of the predicates return true.  This is from Paul
  Graham's ``ANSI Common Lisp'' and is based upon the conjoin function from
  Dylan, a programming language which he describes as a ``cross between Scheme
  and Common Lisp, with a syntax like Pascal.''"
    (assert (or (functionp predicate)
                (symbolp predicate)))
    (dolist (predicate predicates)
  