CLIPS：不是 class 实例匹配周围的条件元素

Question

我读到

CLIPS also gives you the capability of specifying an explicit not conditional element on the LHS. The absence of a fact is specified as a pattern on the LHS using the “not” conditional element.

然而，下面的代码给了我 [PRNTUTIL2] Syntax Error: Check appropriate syntax for the not conditional element.

(not
    (object (is-a clips_ASDF)
        (name ?some_name)
        (property ?my_property_var))
    (test (eq ?my_property_var nil)))

但这不会导致错误：

    (object (is-a clips_ASDF)
        (name ?some_name)
        (property ?my_property_var))
    (not
        (test (eq ?my_property_var nil)))

这是为什么？我该怎么做第一个？

Answer 1

这应该符合您的需要：

(defrule my-rule      
    (object (is-a clips_ASDF) (name ?some_name) (property ?my_property_var)&:(neq ? my_property_var nil))
    =>
    (printout t "done" crlf))

Answer 2

not条件元素只能can一个条件元素。如果要放置多个，请用和条件元素包围它们：

   (not (and (object (is-a clips_ASDF)
                     (name ?some_name)
                     (property ?my_property_var))
             (test (eq ?my_property_var nil))))

或者，不需要单独的 test 条件元素：

   (not (object (is-a clips_ASDF)
                (name ?some_name)
                (property nil)))

CLIPS：不是 class 实例匹配周围的条件元素

CLIPS: Not conditional element around class instance match

clips