我不認爲有更新記錄的ñ個分量的統一方式,你基本上必須「展開」更新的定義:當更新數組a時,你基本上假設「所有的j,無論i是j還是a [j]因此是新值,或者[j]舊值「。由於創紀錄的有窮個元素,可以展開相應的更新定義:
(declare-datatypes (T1 T2) ((Pair (mk-pair (first T1) (second T2)))))
(declare-const p1 (Pair Int Int))
(assert (= (first p1) 1))
(assert (= (second p1) 2)) ;; p1 is (1, 2)
(declare-const p2 (Pair Int Int))
(assert
(and
(= (first p2) (first p1))
(= (second p2) 0)))
(check-sat)
(get-model) ;; p2 could be (1, 0)
這不是爲具有內置更新功能簡潔,但確定;特別是如果您的SMT代碼是由工具生成的。
你也可以引入更新的關係(函數符號和量詞會的工作,太多,但可能會出現問題,由於觸發):
;; Read: "updating p1's second element to v yields p2"
(define-fun setSecond ((p1 (Pair Int Int)) (v Int) (p2 (Pair Int Int))) Bool ;; analogous for setFirst
(and
(= (first p2) (first p1))
(= (second p2) v)))
(declare-const p3 (Pair Int Int))
(assert (setSecond p2 77 p3))
(check-sat)
(get-model) ;; p3 is (1, 77)
,或者更一般地說:
;; Read: "updating p1's ith element to v yields p2"
(define-fun setNth ((p1 (Pair Int Int)) (i Int) (v Int) (p2 (Pair Int Int))) Bool
(and
(= (first p2) (ite (= i 1) v (first p1)))
(= (second p2) (ite (= i 2) v (second p1)))))
(declare-const p4 (Pair Int Int))
(assert (setNth p3 1 -77 p4))
(check-sat)
(get-model) ;; p4 is (-77, 77)
和以前一樣,直接從特定記錄的定義中生成更新函數。
注意:多態函數尚未支持,您需要一個函數setNth_T1_T2
每個元素類型T1
,T2
您的配對可以擁有。