[抱歉，我知道这个问题很多，但是我已经做了很多研究，但我根本不知道如何解决这个问题。我已经在PROLOG中表示了一个管图，需要编写一个谓词来返回两个站点之间的所有路线。我知道我需要使用递归，并尝试了很多不同的解决方案，但是都没有用。我的事实是：
station('AL',[metropolitan]).%Aldgate on the Metropolitan Line
station('BG',[central]).%Bethnal Green on the Central Line
station('BR',[victoria]).%Brixton on the Victoria Line
station('BS',[metropolitan]).%Baker Street on the Metropolitan Line
station('CL',[central]).%Chancery Lane on the Central Line
station('EC',[bakerloo]).%Elephant & Castle on the Bakerloo Line
station('EM',[bakerloo,northern]).%Embankment on the Bakerloo and Northern Lines
station('EU',[northern]).%Euston on the Northern Line
station('FP',[victoria]).%Finsbury Park on the Victoria Line
station('FR',[metropolitan]).%Finchley Road on the Metropolitan Line
station('KE',[northern]).%Kennington on the Northern Line
station('KX',[metropolitan,victoria]).%Kings Cross on the Metropolitan and Victoria Lines
station('LG',[central]).%Lancaster Gate on the Central Line
station('LS',[central,metropolitan]).%Liverpool Street on the Central and Metropolitan Lines
station('NH',[central]).%Notting Hill Gate on the Central Line
station('OC',[bakerloo,central,victoria]).%Oxford Circus on the Bakerloo, Central and Victoria Lines
station('PA',[bakerloo]).%Paddington on the Bakerloo Line
station('TC',[central,northern]).%Tottenham Court Road on the Central and Northern Lines
station('VI',[victoria]).%Victoria on the Victoria Line
station('WA',[bakerloo]).%Warwick Avenue on the Bakerloo Line
station('WS',[northern,victoria]).%Warren Street on the Northern and Victoria Lines
adjacent('WA','PA').%Warwick Avenue is adjacent to Paddington
adjacent('PA','OC').%Paddington is adjacent to Oxford Circus
adjacent('OC','EM').%Oxford Circus is adjacent to Embankment
adjacent('EM','EC').%Embankment is adjacent to Elephant & Castle
adjacent('NH','LG').%Notting Hill Gate is adjacent to Lancaster Gate
adjacent('LG','OC').%Lancaster Gate is adjacent to Oxford Circus
adjacent('OC','TC').%Oxford Circus is adjacent to Tottenham Court Road
adjacent('TC','CL').%Tottenham Court Road is adjacent to Chancery Lane
adjacent('CL','LS').%Chancery Lane is adjacent to Lviverpool Street
adjacent('LS','BG').%Liverpool Street is adjacent to Bethnal Green
adjacent('FR','BS').%Finchley Road is adjacent to Baker Street
adjacent('BS','KX').%Baker Street is adjacent to Kings Cross
adjacent('KX','LS').%Kings Cross is adjacent to Liverpool Street
adjacent('LS','AL').%Liverpool Street is adjacent to Algate
adjacent('EU','WS').%Euston is adjacent Warren Street
adjacent('WS','TC').%Warren Street is adjacent to Tottenham Court Road
adjacent('TC','EM').%Tottenham Court Road is adjacent to Embankment
adjacent('EM','KE').%Embankment is adjacent to Kennington
adjacent('BR','VI').%Brixton is adjacent to Victoria
adjacent('VI','OC').%Victoria is adjacent to Oxford Circus
adjacent('OC','WS').%Oxford Circus is adjacent to Warren Street
adjacent('WS','KX').%Warrent Street is adjacent to Kings Cross
adjacent('KX','FP').%Kings Cross is adjacent to Finsbury Park
我尝试过的解决方案是：
route(From,To,Route) :-
routeattempt(From,To,[From],Route),
reverse(Route,route).
routeattempt(From,To,Inbetween,Route) :-
adjacent(From,To),
\+member(From,Inbetween),
Route = [From|Inbetween].
routeattempt(From,To,Visited,Route) :-
adjacent(From,Inbetween),
Inbetween \== To,
\+member(Inbetween,Visited),
routeattempt(Inbetween,To,Inbetween|Visited],Route).
但是它只会对任何输入返回false。如果有人可以帮助，那就太好了。
这很困惑。
输入
route(From,To,Route) :-
routeattempt(From,To,[From],Route),
reverse(Route,route).
[routeattempt/4的想法显然是“找到从From到To的路由，将其存储为站点列表，存储在Route中。但是参数3，这里的[From]到底是做什么的？”似乎是访问过的电台列表，但是您真的需要吗？您已经有Route。
现在您必须使用小写：From或To相邻：
routeattempt(From,To,Inbetween,Route) :-
adjacent(From,To),
\+member(From,Inbetween),
Route = [From|Inbetween].
或者它们不是：
routeattempt(From,To,Visited,Route) :-
adjacent(From,Inbetween),
Inbetween \== To,
\+member(Inbetween,Visited),
routeattempt(Inbetween,To,Inbetween|Visited],Route).
在第一种情况（基本情况）中，不清楚为什么检查From是否为Inbetween的成员。实际上，这将排除在两个相邻站点之间找到任何路由的可能性，因为route/3已经将From存放到列表Inbetween中。并且不应该两个相邻站点之间的路由不只是[From,To]而不是[From|Inbetween]吗？
[在第二种情况下，您是通过From站从To转到Inbetween，该站也不等于To，尚未被访问过。好的。但是您需要在递归调用之后完成Route。
尝试在format("Current route from ~w to ~w: ~w\n", [From, To, Route])之前添加adjacent/2，然后看看会发生什么。