我在 Prolog 中定义了一个 STRIPS Planner 来解决逻辑问题。在对其他更简单的问题进行了几次尝试后，我开始看看它是否可以解决更复杂的问题。我给了他一个 STRIPS 对 peg solitaire 的定义，英文版，考虑到我们不能做对角线移动，最后一个球会落在棋盘的中央，然后尝试了一下，程序进入了循环。这是问题所在： https ://en.wikipedia.org/wiki/Peg_solitaire
这是我的解决方案：
%%%%%%%%%%%%%%%%%%%%%% PLAN %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
accao(nome : move(Xi,Yi,Xf,Yf),
condicoes : [empty(Xf,Yf),ball(Xi,Yi), ball(Xm,Ym)],
efeitos : [ball(Xf,Yf), -ball(Xm,Ym),-ball(Xi,Yi), empty(Xi,Yi), empty(Xm,Ym), -empty(Xf,Yf)],
restricoes : [abs(Xf-Xi)+abs(Yf-Yi)=:=2, abs(Xf-Xi)*abs(Yf-Yi)=:=0, Xi=<Xm, Xm=<Xf, Yi=<Ym, Ym=<Yf]).
inicial([empty(5,5), ball(1,4), ball(1,5), ball(1,6),
ball(2,4), ball(2,5), ball(2,6),
ball(3,4), ball(3,5), ball(3,6),
ball(4,1), ball(4,2), ball(4,3),ball(4,4), ball(4,5), ball(4,6),ball(4,7), ball(4,8), ball(4,9),
ball(5,1), ball(5,2), ball(5,3),ball(5,4), ball(5,6),ball(5,7), ball(5,8), ball(5,9),
ball(6,1), ball(6,2), ball(6,3),ball(6,4), ball(6,5), ball(6,6),ball(6,7), ball(6,8), ball(6,9),
ball(7,4), ball(7,5), ball(7,6),
ball(8,4), ball(8,5), ball(8,6),
ball(9,4), ball(9,5), ball(9,6)]).
objectivos([ball(5,5), empty(1,4), empty(1,5), empty(1,6),
empty(2,4), empty(2,5), empty(2,6),
empty(3,4), empty(3,5), empty(3,6),
empty(4,1), empty(4,2), empty(4,3),empty(4,4), empty(4,5), empty(4,6),empty(4,7), empty(4,8), empty(4,9),
empty(5,1), empty(5,2), empty(5,3),empty(5,4), empty(5,6),empty(5,7), empty(5,8), empty(5,9),
empty(6,1), empty(6,2), empty(6,3),empty(6,4), empty(6,5), empty(6,6),empty(6,7), empty(6,8), empty(6,9),
empty(7,4), empty(7,5), empty(7,6),
empty(8,4), empty(8,5), empty(8,6),
empty(9,4), empty(9,5), empty(9,6)]).
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
%%%%%%%%%%%%%%%%%%%%%% PRINT FUNCTION %%%%%%%%%%%%%%%%%%%%%%%%%%%
printExec([]).
printExec([A,E|T]) :- write("Action performed: "),
write(A),nl,
write("Situation: "),
write(E),nl,
printExec(T).
writeExec([I|T]):- write("Initial Situation"),
write(I),nl,
printExec(T),
write("Goal: "),
objectivos(G),
write(G),
write(" satisfied."),nl.
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
%%%%%%%%%%%%%%%%%%%% AUXILIAR FUNCTIONS %%%%%%%%%%%%%%%%%%%%%%%%%
member(E,[E|_]).
member(E,[_|T]):-member(E,T).
sub([],_).
sub([H|T],L):- member(H,L),
sub(T,L).
remove(_,[],[]):-!.
remove(E1, [E2|T], T):- E1 == E2, !.
remove(E,[H|T1],[H|T2]):- remove(E,T1,T2).
add(E,[],[E]):-!.
add(E1,[E2|T],[E1,E2|T]):- E1 \== E2, !.
add(E,[H|T1],[H|T2]):-add(E,T1,T2).
effects([],S,S).
effects([-H|Fx],S,N) :-!,
remove(H,S,NS),
effects(Fx,NS,N).
effects([H|Fx],S,N) :- !,
add(H,S,NS),
effects(Fx,NS,N).
restriction([]).
restriction([R|T]) :- R,
restriction(T).
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
%%%%%%%%%%%%%%%%%%%%%%% PLAN EXECUTE %%%%%%%%%%%%%%%%%%%%%%%%%%%
planExecute(P):-testPlan(P,E),writeExec(E),!.
satisfiedGoal(E):- objectivos(Fn),!,
sub(Fn,E).
testPlan(Plan,[I|Exec]) :- inicial(I),
testPlan(Plan,I,Exec,Fn),
satisfiedGoal(Fn).
testPlan([],Fn,[],Fn).
testPlan([H|T],S,[H,N|Exec],Fn) :- accao(nome:H, condicoes:C,efeitos:E, restricoes:R),
sub(C,S),
effects(E,S,N),
restriction(R),
testPlan(T,N,Exec,Fn).
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
%%%%%%%%%%%%%%%%%%%%%%% FIND PLAN %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
plano(P) :- progressivePlan(P, 0).
progressivePlan(P, N) :- createPlan(P,_,0,N).
progressivePlan(P, N) :- \+ createPlan(P,_,0,N),
NewN is N + 1,
progressivePlan(P, NewN).
createPlan(Plan,[I|Exec],N,Max) :- inicial(I),
createPlan(Plan,I,Exec,Fn,N,Max),
satisfiedGoal(Fn).
createPlan([],Fn,[],Fn,Max,Max):- !.
createPlan([H|T],S,[H,N|Exec],Fn,Acc, Max) :- accao(nome:H, condicoes:C, efeitos:E, restricoes:R),
sub(C,S),
effects(E,S,N),
restriction(R),
NewAcc is Acc+1,
createPlan(T,N,Exec,Fn,NewAcc, Max).
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%`
我尝试通过只做一两个动作来简化目标，这适用于一个动作，并且当两个动作不相互矛盾时，例如将弹珠移过已经移动的弹珠，通过两个动作进入循环当他们这样做时，就像所说的目标一样：
objectivos（[球（4,5），空（3,5），空（5,5），空（6,5）]）。
我已经尝试过跟踪和调试，但我似乎找不到问题，尽管我相信它位于问题的制定中，而不是 Planner 本身。有任何想法吗？