List 在Prolog中设置两个兼容列表的差异

我目前正试图在prolog中实现一个自动化的定理证明程序，但偶然发现了一个问题

如果我有一个列表，例如：

[[1,2],[-1,3],[4,5,7],[-2,4]]

如何获得两个兼容列表项的“设置差异”： 我所说的兼容是指，如果某个数字的否定存在于另一个列表中，则用集合差替换这两个列表，即：

[1,2]

和

[-1,3]

是兼容的，因为第二个子句中存在

-1

，因此它应该返回

[2,3]

的设置差，新列表应该是

[[2,3]，[4,5,7]，-2,4]

目前我有以下

步骤

谓词：

memberlist(X,[[X|_]|_]).
memberlist(X,[[_|T1]|T2]) :-
    memberlist(X,[T1|T2]).
memberlist(X,[[]|T2]) :-
    memberlist(X,T2).

step([]).
step([_|T]) :-
    memberlist(neg X,T),
    write(X),
    nl,
    step(T).
step([_|T]) :-
    step(T).

因此，它只是检查每个列表，检查变量的否定是否存在，以及是否将其写出。我已经添加了处理负数的代码，因此

X

将匹配

-X

，

X

是任意整数

---

我在这一点上非常困惑，任何帮助都将不胜感激。

另一种配方

• memberlist

  将为您提供三元组

  p（X，Y，Z）

  其中

  Z

  和

  neg（Z）

  位于

  X

  和

  Y

  中
• 折叠将采用这样一个三元组，并从

  Xs

  中删除

  X

  ，

  Y

  ，然后向其添加

  X+Y-Z-neg（Z）

你的榜样

?- collapse([[1, 2], [neg(1), 3], [4, 5, 7], [neg(2), 4]], X).
X = [[2, 3], [4, 5, 7], [neg(2), 4]] ;
X = [[1, 4], [neg(1), 3], [4, 5, 7]] ;
false.

---

另一种可能的解决办法：

shrink([L1|R1], [L3|R2]) :-
    select(L2, R1, R2),
    difference(L1, L2, L3).
shrink([L1|R1], [L1|S]) :-
    shrink(R1, S).

difference(L1, L2, L3) :-
    select(X, L1, R1),
    compatible(X, Y),
    select(Y, L2, R2),
    union(R1, R2, L3).

compatible(neg(P), P) :- !.
compatible(P, neg(P)).

一些例子：

?- shrink([[1,2], [neg(1),3], [4,5,6], [neg(2),4]], S).
S = [[2, 3], [4, 5, 6], [neg(2), 4]] ;
S = [[1, 4], [neg(1), 3], [4, 5, 6]] ;
false.

?- shrink([[a,neg(b)], [a,b]], S).
S = [[a]] ;
false.

?- shrink([[rainning], [neg(rainning)]], S).
S = [[]] ;
false.

?- shrink([[rainning], [neg(rainning), wet_grass], [neg(wet_grass), green_grass]], S).
S = [[wet_grass], [neg(wet_grass), green_grass]] ;
S = [[rainning], [neg(rainning), green_grass]] ;
false.

?- shrink([[neg(green_grass)], [rainning], [neg(rainning), wet_grass], [neg(wet_grass), green_grass]], A), shrink(A, B), shrink(B, C).

A = [[neg(wet_grass)], [rainning], [neg(rainning), wet_grass]],
B = [[neg(rainning)], [rainning]],
C = [[]] ;

A = [[neg(wet_grass)], [rainning], [neg(rainning), wet_grass]],
B = [[neg(wet_grass)], [wet_grass]],
C = [[]] ;

A = [[neg(green_grass)], [wet_grass], [neg(wet_grass), green_grass]],
B = [[neg(wet_grass)], [wet_grass]],
C = [[]] ;

A = [[neg(green_grass)], [wet_grass], [neg(wet_grass), green_grass]],
B = [[neg(green_grass)], [green_grass]],
C = [[]] ;

A = [[neg(green_grass)], [rainning], [neg(rainning), green_grass]],
B = [[neg(rainning)], [rainning]],
C = [[]] ;

A = [[neg(green_grass)], [rainning], [neg(rainning), green_grass]],
B = [[neg(green_grass)], [green_grass]],
C = [[]] ;
false.

---

这是在SWI Prolog上交叉发布的。谢谢你的解决方案，兄弟！我非常感激：）我想投票，但我还没有这个特权！

?- shrink([[1,2], [neg(1),3], [4,5,6], [neg(2),4]], S).
S = [[2, 3], [4, 5, 6], [neg(2), 4]] ;
S = [[1, 4], [neg(1), 3], [4, 5, 6]] ;
false.

?- shrink([[a,neg(b)], [a,b]], S).
S = [[a]] ;
false.

?- shrink([[rainning], [neg(rainning)]], S).
S = [[]] ;
false.

?- shrink([[rainning], [neg(rainning), wet_grass], [neg(wet_grass), green_grass]], S).
S = [[wet_grass], [neg(wet_grass), green_grass]] ;
S = [[rainning], [neg(rainning), green_grass]] ;
false.

?- shrink([[neg(green_grass)], [rainning], [neg(rainning), wet_grass], [neg(wet_grass), green_grass]], A), shrink(A, B), shrink(B, C).

A = [[neg(wet_grass)], [rainning], [neg(rainning), wet_grass]],
B = [[neg(rainning)], [rainning]],
C = [[]] ;

A = [[neg(wet_grass)], [rainning], [neg(rainning), wet_grass]],
B = [[neg(wet_grass)], [wet_grass]],
C = [[]] ;

A = [[neg(green_grass)], [wet_grass], [neg(wet_grass), green_grass]],
B = [[neg(wet_grass)], [wet_grass]],
C = [[]] ;

A = [[neg(green_grass)], [wet_grass], [neg(wet_grass), green_grass]],
B = [[neg(green_grass)], [green_grass]],
C = [[]] ;

A = [[neg(green_grass)], [rainning], [neg(rainning), green_grass]],
B = [[neg(rainning)], [rainning]],
C = [[]] ;

A = [[neg(green_grass)], [rainning], [neg(rainning), green_grass]],
B = [[neg(green_grass)], [green_grass]],
C = [[]] ;
false.