anchor.diff:          (lambda (binding)
             (if (consp binding)
                 (cons (first binding)
  -                    (formatexpand-forms-partially (rest binding) ~))
  +                    (formatexpand-forms (rest binding) ~))
                 binding))
           bindings)
         ,@body)))
  
positive.code:       ,@(mapcar
           (lambda (case)
             (cons (first case)
                   (formatexpand-forms-partially (rest case) ~)))
           cases)))
  
    (defun expand-letlike (operator ~ bindings body)
  
negative.code: 
  (define-~format if (~) (test then &optional (else nil elsep))
    `(if ,test
         ,(formatexpand then ~)
         ,@(when elsep (list (formatexpand else ~)))))
  
  (define-~format when (~) (test &rest body)
    `(when ,test
       ,@(formatexpand-forms body ~)))
  
  (define-~format unless (~) (test &rest body)
    `(unless ,test
       ,@(formatexpand-forms body ~)))
  
  (define-~format cond (~) (&rest clauses)
    `(cond ,@(mapcar
              (lambda (clause)
                (cons (first clause)
                      (formatexpand-forms (rest clause) ~)))
                     clauses)))
  
  (eval-when (:compile-toplevel :load-toplevel :execute)
  