anchor.diff:      (error 'malformed-variable-clauses
              :name
              :datum variable-clauses))
  -  (local-mapcar
  +  (mapcar
      (lambda (clause)
        (unless (or (symbolp clause)
   		 (and (consp clause)
  
positive.code:    variable-clauses))
  
  (defun extract-bindings (variable-clauses)
    (local-mapcar
     (lambda (clause)
       (cond ((symbolp clause) clause)
  	   ((null (cdr clause)) (car clause))
  
negative.code:            :name name
             :datum body)))
  
  (defun local-mapcar (function list)
    (if (null list)
        '()
  