anchor.diff:  		(cdr tokens))
   	(values nil nil tokens))))
   
  -(define-parser destructured-type-spec
  +(define-parser destructured-type-spec-parser
     (consecutive (lambda (of-type tree)
   		 (declare (ignore of-type))
   		 (make-instance 'destructured-type-spec
  
positive.code: ;;;
  ;;; Parser
  
  (define-parser simple-type-spec
    (lambda (tokens)
      (if (and (not (null tokens))
  	     (member (car tokens) '(fixnum float t nil)))
  
negative.code: 	       (keyword-parser 'of-type)
  	       (singleton #'identity (constantly t))))
  
  (define-parser type-spec-parser
    (alternative 'simple-type-spec 'destructured-type-spec))
  