In PL/1, a function procedure( programmer-specified or built-in), a procedure that is invoked by the appearance of one of its entry names in a function reference and which returns a value to the point reference.

• 在pl/语言中，一种函数过程（序员规定的或内部的）在引用函数时，出现一个函数过程名就调用一次过程，并返回一个值给引用点。