anchor.diff:          (yield (car (conjunctive-op-expressions op))))))
   
   (defmethod yield ((op function-op))
  -  (with-yield-binds
  -    (format nil "~A(~{~A~^, ~})"
  -            (sql-op-name op)
  -            (mapcar #'yield (function-op-expressions op)))))
  +  (let ((*inside-function-op* t))
  +    (with-yield-binds
  +      (format nil "~A(~{~A~^, ~})"
  +              (sql-op-name op)
  +              (mapcar #'yield (function-op-expressions op))))))
   
   (defmethod yield ((clause expression-clause))
     (multiple-value-bind (sql bind)
  
positive.code: 
  (defparameter *bind-values* nil)
  (defparameter *use-global-bind-values* nil)
  
  @export
  (defmacro with-yield-binds (&body body)
  
negative.code: 
  (defmethod yield ((statement sql-composed-statement))
    (with-yield-binds
      (format nil (if *inside-function-op*
                      "(~A ~{~A~^ ~})"
                      "~A ~{~A~^ ~}")
              (sql-statement-name statement)
              (mapcar #'yield (sql-composed-statement-children statement)))))
  
  