CLIPS规则不匹配

Question

我在Clips中的规则匹配有问题，特别是我不明白为什么这个规则不生效。

(deffunction get-unknow-col (?col)
    (bind ?facts (length (find-all-facts ((?a a-cell)) (and (eq ?a:y ?col) (eq ?a:content unk)))))
    (return ?facts)
)

(deffunction get-boat-pieces-col (?col)
    (bind ?facts (length (find-all-facts ((?a a-cell)) (and (eq ?a:y ?col) (and (neq ?a:content unk) (neq ?a:content water))))))
    (return ?facts)
)

(defrule mark-remaining-unk-cells-col (declare (salience 40))
    (k-per-col (col ?y) (num ?num))
    (test (= (+ (get-unknow-col ?y) (get-boat-pieces-col ?y)) ?num))
=>
    (do-for-all-facts ((?cell a-cell)) (and (eq ?cell:y ?y) (eq ?cell:content unk))
        (modify ?cell (content boat-piece))
    )
)

但是在(事实)中，我有正确的值，事实上正在运行。

(k-per-col (col 9) (num 1))

(get-unknow-col 9)
1
(get-boat-pieces-col 9)
0
CLIPS> (= (+ (get-unknow-col 9) (get-boat-pieces-col 9)) 1)
TRUE

该规则只有在num为0的情况下才会生效（正确）。

FIRE   75 mark-remaining-unk-cells-col: f-137
***** Y:8 num: 0 get-unknown-col: 0 get-boat-pieces-col 0
FIRE   76 mark-remaining-unk-cells-col: f-136
***** Y:7 num: 0 get-unknown-col: 0 get-boat-pieces-col 0

为什么当num=1, get-unknow-col=1, get-boat-pieces-col=0并且测试为真时，它不激活？我错在哪里？

Answer 1

这是CLIPS基本编程指南第5.4.2节测试条件元素的相关行为描述。

当所有进行中的CE都被满足时，测试CE将被评估。这意味着，如果一个测试CE可以被不止一组模式实体满足，那么一个测试CE将被评估一次以上。为了引起测试CE的重新评估，必须改变与测试CE之前的CE相匹配的模式实体。

当k-per-col事实被断言时，测试CE将被评估。如果这发生在任何或所有a-cell事实被断言之前，那么您将不会得到与先断言所有a-cell事实然后断言k-per-col事实相同的结果。

为了确保可预测的行为，由测试 CE 评估的表达式应该总是为一组特定的参数返回相同的值。在这种情况下，get-unknow-col和get-boat-pieces-col函数可以返回不同的值，即使参数?col与前一次调用相同。

一些基于规则的语言提供了一个 "collect "的条件元素，可以很容易地统计出与模式相匹配的事实数量，但遗憾的是CLIPS没有提供这个功能。为了增加这个功能，你需要创建跟踪感兴趣值的事实和规则。

         CLIPS (6.31 6/12/19)
CLIPS> 
(deftemplate a-cell
   (slot id (default-dynamic (gensym*))) 
   (slot x)
   (slot y)
   (slot content (allowed-values water left right middle top bot sub unk)))
CLIPS> 
(deftemplate track-a-cell
   (slot x (default any))
   (slot y (default any))
   (slot content (default any))
   (multislot matches))
CLIPS>    
(deffacts trackers
   (track-a-cell (x any) (y 9) (content unk)))
CLIPS>    
(defrule add-a-cell-match
   (declare (salience 10))
   ?t <- (track-a-cell (x ?x1) (y ?y1) (content ?c1) (matches $?m))
   (a-cell (id ?id) (x ?x2) (y ?y2) (content ?c2))
   (test (and (not (member$ ?id ?m))
              (or (eq ?x1 any) (eq ?x1 ?x2))
              (or (eq ?y1 any) (eq ?y1 ?y2))
              (or (eq ?c1 any) (eq ?c1 ?c2))))
   =>
   (modify ?t (matches ?m ?id)))
CLIPS>    
(defrule remove-a-cell-match
   (declare (salience 10))
   ?t <- (track-a-cell (x ?x1) (y ?y1) (content ?c1) (matches $?b ?id $?e))
   (not (and (a-cell (id ?id) (x ?x2) (y ?y2) (content ?c2))
             (test (and (or (eq ?x1 any) (eq ?x1 ?x2))
                            (or (eq ?y1 any) (eq ?y1 ?y2))
                            (or (eq ?c1 any) (eq ?c1 ?c2))))))
   =>
   (modify ?t (matches ?b ?e)))
CLIPS> 
(deffacts init
   (a-cell (x 0) (y 9) (content water))
   (a-cell (x 1) (y 9) (content unk))
   (a-cell (x 2) (y 9) (content water))
   (a-cell (x 3) (y 9) (content water))
   (a-cell (x 5) (y 9) (content water))
   (a-cell (x 6) (y 9) (content unk))
   (a-cell (x 7) (y 9) (content water))
   (a-cell (x 8) (y 9) (content water))
   (a-cell (x 9) (y 9) (content water))
   (a-cell (x 4) (y 9) (content unk)))
CLIPS> (reset)
CLIPS> (run)
CLIPS> (facts)
f-0     (initial-fact)
f-2     (a-cell (id gen1) (x 0) (y 9) (content water))
f-3     (a-cell (id gen2) (x 1) (y 9) (content unk))
f-4     (a-cell (id gen3) (x 2) (y 9) (content water))
f-5     (a-cell (id gen4) (x 3) (y 9) (content water))
f-6     (a-cell (id gen5) (x 5) (y 9) (content water))
f-7     (a-cell (id gen6) (x 6) (y 9) (content unk))
f-8     (a-cell (id gen7) (x 7) (y 9) (content water))
f-9     (a-cell (id gen8) (x 8) (y 9) (content water))
f-10    (a-cell (id gen9) (x 9) (y 9) (content water))
f-11    (a-cell (id gen10) (x 4) (y 9) (content unk))
f-14    (track-a-cell (x any) (y 9) (content unk) (matches gen10 gen6 gen2))
For a total of 12 facts.
CLIPS> (retract 3 7)
CLIPS> (run)
CLIPS> (facts)
f-0     (initial-fact)
f-2     (a-cell (id gen1) (x 0) (y 9) (content water))
f-4     (a-cell (id gen3) (x 2) (y 9) (content water))
f-5     (a-cell (id gen4) (x 3) (y 9) (content water))
f-6     (a-cell (id gen5) (x 5) (y 9) (content water))
f-8     (a-cell (id gen7) (x 7) (y 9) (content water))
f-9     (a-cell (id gen8) (x 8) (y 9) (content water))
f-10    (a-cell (id gen9) (x 9) (y 9) (content water))
f-11    (a-cell (id gen10) (x 4) (y 9) (content unk))
f-16    (track-a-cell (x any) (y 9) (content unk) (matches gen10))
For a total of 10 facts.
CLIPS> (assert (a-cell (x 1) (y 9) (content unk)))
<Fact-17>
CLIPS> (run)
CLIPS> (facts)
f-0     (initial-fact)
f-2     (a-cell (id gen1) (x 0) (y 9) (content water))
f-4     (a-cell (id gen3) (x 2) (y 9) (content water))
f-5     (a-cell (id gen4) (x 3) (y 9) (content water))
f-6     (a-cell (id gen5) (x 5) (y 9) (content water))
f-8     (a-cell (id gen7) (x 7) (y 9) (content water))
f-9     (a-cell (id gen8) (x 8) (y 9) (content water))
f-10    (a-cell (id gen9) (x 9) (y 9) (content water))
f-11    (a-cell (id gen10) (x 4) (y 9) (content unk))
f-17    (a-cell (id gen11) (x 1) (y 9) (content unk))
f-18    (track-a-cell (x any) (y 9) (content unk) (matches gen10 gen11))
For a total of 11 facts.
CLIPS>