AHABHGK

1/* 事实 */
2likes(tom, jack).
3likes(teacherma, pony).
4likes(jerry, pony).
5likes(jerry, teacherma).
6
7/* 规则 */
8/* \+ 取反 \+(X = Y) 表示 X 不等于 Y，, 逗号分割子目标，都是真才真 */
9friend(X, Y) :- \+(X = Y), likes(X, Z), likes(Y, Z).

1-? friend(teacherma, jerry)
2true.
3
4-? likes(jerry, Who).
5Who = pony ;
6Who = teacherma.

1color(red).
2color(green).
3color(blue).
4
5colorify(A,B,C,D,E) :-
6    color(A), color(B), color(C), color(D), color(E),
7    \+ A=B, \+ A=C, \+ A=D, \+ A=E,
8    \+ B=C, \+ C=D, \+ D=E.

1?- colorify(A,B,C,D,E).
2A = red,
3B = D, D = green,
4C = E, E = blue;
5A = red,
6B = D, D = blue,
7C = E, E = green ;
8A = green,
9B = D, D = red,
10C = E, E = blue ;
11A = green,
12B = D, D = blue,
13C = E, E = red ;
14A = blue,
15B = D, D = red,
16C = E, E = green ;
17A = blue,
18B = D, D = green,
19C = E, E = red ;

1father(a, b).
2father(b, c).
3father(c, d).
4father(d, e).
5
6ancestor(X, Y) :- father(X, Y).
7ancestor(X, Y) :- father(X, Z), ancestor(Z, Y).

1?- ancestor(a, Who).
2Who = b ;
3Who = c ;
4Who = d ;
5Who = e ;
6false.

1?- (1, 2, 3) = (1, 2, 3)
2true
3?- [1, 2, 3] = [1, 2, 3]
4true
5?- (A, 2, C) = (1, B, 3)
6A = 1
7B = 2
8C = 3
9?- [A, 2, C] = [1, B, 3]
10A = 1
11B = 2
12C = 3
13?- [a, b, c, d, e] = [_, _| [Head | Tail]]
14Head = c
15Tail = [d, e]

1count(0, []).
2count(Count, [_| Tail]) :- count(TailCount, Tail), Count is TailCount + 1.
3
4sum(0, []).
5sum(Total, [Head| Tail]) :- sum(Sum, Tail), Total is Head + Sum.
6
7average(Average, List) :- sum(Sum, List), count(Count, List), Average is Sum / Count.

1append([], List, List).
2append([Head| List1], List2, [Head| Tail]) :- append(List1, List2, Tail).

1?- append(L1, L2, [1, 2, 3, 1, 5]).
2L1 = [],
3L2 = [1, 2, 3, 1, 5] ;
4L1 = [1],
5L2 = [2, 3, 1, 5] ;
6L1 = [1, 2],
7L2 = [3, 1, 5] ;
8L1 = [1, 2, 3],
9L2 = [1, 5] ;
10L1 = [1, 2, 3, 1],
11L2 = [5] ;
12L1 = [1, 2, 3, 1, 5],
13L2 = [] ;
14false