我有一个家庭作业，要在序言中定义 10 个事实来解决这个难题。
Five translators are working in an international organization:
Spaniard, Englishman, Frenchman, German and Russian.
Each of them speaks its native language and also two
languages from the native languages of other translators. Find
the languages speaked by each translator if it is known that
1. The Englishman speaks German.
2. The Spaniard speaks French.
3. The German does not speak Spanish.
4. The Frenchman does not speak German.
5. Spaniard and Englishman can talk with each other in German.
6. Englishman and Frenchman can talk with each other in two
languages.
7. Four translators speak Russian.
8. Exactly two translators speak French.
9. Only one translator who speaks Spanish speaks also Russian.
10. Russian and Englishman have no common languages except
their native languages.
我已经定义了 8 个约束并将我的解决方案空间减少到 15 个。但我不知道如何定义最后两个事实。
% lahendusstruktuur
structure(
[translator(inglane,_,_,inglise),
translator(sakslane,_,_,saksa),
translator(hispaanlane,_,_,hispaania),
translator(prantslane,_,_,prantsuse),
translator(venelane,_,_,vene)]).
% abipredikaadid
nationality(translator(B,_,_,_),B).
language1( translator(_,B,_,_),B).
language2( translator(_,_,B,_),B).
native_language(
translator(_,_,_,B),B).
% keelte faktid (andmebaas)
possible_language(vene).
possible_language(inglise).
possible_language(hispaania).
possible_language(prantsuse).
possible_language(saksa).
% tabeli täitmine
solve(S):-
structure(S),
fill_structure(S),
fact1(S),
fact2(S),
fact3(S),
fact4(S),
fact5(S),
fact6(S),
fact7(S),
fact8(S),
%fact9(S),
%fact10(S),
true.
fill_structure([A,B,C,D,E]):-
fill_line(A,inglane),
fill_line(B,sakslane),
fill_line(C,hispaanlane),
fill_line(D,prantslane),
fill_line(E,venelane).
fill_line(X,Nationality):-
nationality(X,Nationality),
possible_language(Keel1),
language1(X,Keel1),
possible_language(Keel2),
language2(X,Keel2),
native_language(X,Native),
Keel1\=Native,
Keel2\=Native,
Keel1 @> Keel2.
% keelte generaator
speaks(Nationality,Language,S):-
member(X,S),
nationality(X,Nationality),
language(X,Language).
language(X,L):-native_language(X,L).
language(X,L):-language1(X,L).
language(X,L):-language2(X,L).
% faktid 1-10
%1. The Englishman speaks German.
fact1(X):-
speaks(inglane,saksa,X).
%2. The Spaniard speaks French.
fact2(X):-
speaks(hispaanlane,saksa,X).
%3. The German does not speak Spanish.
fact3(X):-
\+speaks(sakslane,hispaania,X).
% The Frenchman does not speak German.
fact4(X):-
\+speaks(prantslane,saksa,X).
% Spaniard and Englishman can talk with each other in German.
fact5(X):-
speaks(hispaanlane,saksa,X),
speaks(inglane,saksa,X).
%6. Englishman and Frenchman can talk with each other in two languages.
fact6(X):-
findall(Keel,
(
speaks(inglane,Keel,X),
speaks(prantslane,Keel,X)
),
Keelte_hulk),
Keelte_hulk=[_,_].
%% Four translators speak Russian.
fact7(X):-
findall(Inimene,
(
speaks(Inimene,vene,X),
speaks(Inimene,vene,X),
speaks(Inimene,vene,X),
speaks(Inimene,vene,X)),Inimeste_hulk),
Inimeste_hulk=[_,_,_,_].
/*
(speaks(inglane,vene,X),
speaks(sakslane, vene,X),
speaks(hispaanlane, vene,X),
\+ speaks(prantslane, vene,X));
(speaks(inglane,vene,X),
speaks(sakslane, vene,X),
\+speaks(hispaanlane, vene,X),
speaks(prantslane, vene,X));
(speaks(inglane,vene,X),
\+speaks(sakslane, vene,X),
speaks(hispaanlane, vene,X),
speaks(prantslane, vene,X));
(speaks(inglane,vene,X),
\+speaks(sakslane, vene,X),
speaks(hispaanlane, vene,X),
speaks(prantslane, vene,X)). */
%Exactly two translators speak French.
fact8(X):-
findall(Inimene,
(
speaks(Inimene,prantsuse,X),
speaks(Inimene,prantsuse,X)),Inimeste_hulk),
Inimeste_hulk=[_,_].
例如，我为事实 10 尝试了这样的解决方案。
fact10(X):-
speaks(inglane,inglise,X), speaks(venelane,inglise,X),
speaks(venelane,inglise,X), speaks(venelane,vene,X),
\=(speaks(inglane,hispaania,X),speaks(venelane, hispaania,X),
\=(speaks(inglane,prantsuse,X),speaks(venelane, prantsuse,X),
\=(speaks(inglane,saksa,X),speaks(venelane,saksa,X).
这减少了解决方案空间，但之后它仍然包含不应该在减少的解决方案集中的元素。
我正在使用这个函数来获取我的解决方案集大小
findall(_, solve(X), Solutions), length(Solutions,N).
这对于解决方案集元素
solve(X).
我不知道如何描述这两个事实。如果有人可以提供帮助，我将不胜感激:)。
对不起，我的英语不是我的母语。