與剪輯中的零比較

Question

如何比較零剪輯中的零？
我試圖

(defrule update-time               
    ?cur-time <- (current-time ?time)           
    (order (event-time ?new-time-o&:(neq ?new-time-o nil)))  

我也曾嘗試

(neq ?new-time-o "nil") 

沒有它似乎工作，我沒有得到任何激活。

Answer 1

您尚未提供足夠的信息來解答您的問題。給定適當的數據，這條規則將激活：

CLIPS> (deftemplate order (slot event-time)) 
CLIPS> 
(defrule update-time               
    ?cur-time <- (current-time ?time)           
    (order (event-time ?new-time-o&:(neq ?new-time-o nil)))  
    =>) 
CLIPS> (assert (order (event-time (time)))) 
<Fact-1> 
CLIPS> (assert (current-time (time))) 
<Fact-2> 
CLIPS> (agenda) 
0  update-time: f-2,f-1 
For a total of 1 activation. 
CLIPS>