anchor.diff:  
   (defparameter *bind-values* nil)
   (defparameter *use-global-bind-values* nil)
  +(defparameter *inside-function-op* nil)
   
   @export
   (defmacro with-yield-binds (&body body)
  
positive.code: 
  (defmethod yield ((statement sql-composed-statement))
    (with-yield-binds
      (format nil "~A ~{~A~^ ~}"
              (sql-statement-name statement)
              (mapcar #'yield (sql-composed-statement-children statement)))))
  
  
negative.code:         (yield (car (conjunctive-op-expressions op))))))
  
  (defmethod yield ((op function-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)
  