anchor.diff:  
   See also: `pfunc', `p+', `p-', `p*', `p/'"
     :defun (defun pnary (operator &rest patterns)
  -           (set-parents
  -            (make-instance 'pnary
  -                           :operator operator
  -                           :patterns patterns))))
  +           (make-instance 'pnary
  +                          :operator operator
  +                          :patterns patterns)))
   
   (defmethod as-pstream ((pnary pnary))
     (with-slots (operator patterns) pnary
  
positive.code:       (setf pstream-count (if (slot-exists-p object 'pstream-count)
                                (slot-value object 'pstream-count)
                                0)
              source object
              history (make-array *max-pattern-yield-length* :initial-element nil)))
      (set-parents pstream)
      pstream))
  
  (defmethod as-pstream :around ((pstream pstream)) ;; prevent pstreams from being "re-converted" to pstreams
  
negative.code: 
  See also: `pbind''s :embed key"
    :defun (defun pchain (&rest patterns)
             (make-instance 'pchain
                            :patterns patterns)))
  
  (defmethod as-pstream ((pchain pchain))
    (with-slots (patterns) pchain
  