Solve the following Caliban problem, translating each clue 'loyally' into Prolog, i.e. as loyally as possible.
As a simple exercise in abstraction suppose that four meaningless symbols a, b, c, and d correspond in one order or another to the equally meaningless symbols w, x, y, and z, and suppose further that
If a is not x, then c is not y.
If b is either y or z, then a is x.
If c is not w, then b is z.
If d is y, then b is not x.
If d is not x, then b is x.In what order do the two sets of symbols correspond?
I tried the following code:
vban(L) :-
L=[[a,C1],[b,C2],[c,C3],[d,C4]],
( member(C1,[w,y,z]) -> member(C3,[w,x,z])),
( member(C2,[y,z]) -> member(C1,[x])),
( member(C3,[x,y,z]) -> member(C2,[z])),
( member(C4,[y]) -> member(C2,[w,y,z])),
( member(C4,[w,y,z]) -> member(C2,[x])).
But it shows fail.Any help would be appreciated.
Using CLP(B) in SICStus Prolog or SWI:
:- use_module(library(clpb)).
:- use_module(library(lists)).
:- use_module(library(clpfd)).
corresponding(Matrix) :-
Matrix = [[ _,AX, _, _],
[ _,BX,BY,BZ],
[CW, _,CY, _],
[ _,DX,DY, _]],
maplist(card1, Matrix),
transpose(Matrix, TMatrix),
maplist(card1, TMatrix),
sat(~AX =< ~CY),
sat(BY + BZ =< AX),
sat(~CW =< BZ),
sat(DY =< ~BX),
sat(~DX =< BX).
card1(Vs) :- sat(card([1], Vs)).
Example query:
?- corresponding(Vs),
pairs_keys_values(Pairs, [t,a,b,c,d], [[w,x,y,z]|Vs]),
maplist(writeln, Pairs).
Yielding (1 denotes corresponding elements):
t-[w,x,y,z]
a-[0,0,1,0]
b-[0,1,0,0]
c-[1,0,0,0]
d-[0,0,0,1]
and bindings for Vs and Pairs.