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  1. % find the Zebra and the Water, zebra_water(X).
  2. % by Willem Robert van Hage, wrvhage@science.uva.nl
  3.  
  4. right(2,1).
  5. right(3,2).
  6. right(4,3).
  7. right(5,4).
  8. nextdoor(X,Y) :- right(X,Y).
  9. nextdoor(X,Y) :- right(Y,X).
  10.  
  11. match([],_).
  12. match([X|Xs],Ys) :-
  13.         member(X,Ys),
  14.         match(Xs,Ys).
  15.  
  16. zebra_water(X) :-
  17.         nextdoor(Horse,Diplomat),
  18.         nextdoor(Fox,Doctor),
  19.         nextdoor(Norwegian,Blue),
  20.         Y = [house(    Green,          _,  green,         _,      _,      _),
  21.              house(    White,          _,  white,         _,      _,      _),
  22.              house(Norwegian,  norwegian,      _,         _,      _,      _),
  23.              house(     Blue,          _,   blue,         _,      _,      _),
  24.              house(      Fox,          _,      _,         _,    fox,      _),
  25.              house(   Doctor,          _,      _,    doctor,      _,      _),
  26.              house(    Horse,          _,      _,         _,  horse,      _),
  27.              house( Diplomat,          _,      _,  diplomat,      _,      _),
  28.              house(        3,          _,      _,         _,      _,   milk),
  29.              house(        1,  norwegian,      _,         _,      _,      _),
  30.              house(        _, englishman,    red,         _,      _,      _),
  31.              house(        _,   spaniard,      _,         _,    dog,      _),
  32.              house(        _,   japanese,      _,   painter,      _,      _),
  33.              house(        _,    italian,      _,         _,      _,    tea),
  34.              house(        _,          _, yellow,  diplomat,      _,      _),
  35.              house(        _,          _,  green,         _,      _, coffee),
  36.              house(        _,          _,      _,  sculptor, snails,      _),
  37.              house(        _,          _,      _, violinist,      _,  juice),
  38.              house(        _,          _,      _,         _,  zebra,      _),
  39.              house(        _,          _,      _,         _,      _,  water) ],
  40.         X = [ house(1,_,_,_,_,_),
  41.               house(2,_,_,_,_,_),
  42.               house(3,_,_,_,_,_),
  43.               house(4,_,_,_,_,_),
  44.               house(5,_,_,_,_,_) ],
  45.         right(Green,White),
  46.         match(Y,X).
Success #stdin #stdout 0.02s 68352KB
comments (?)
stdin 
Standard input is empty
stdout 
GNU Prolog 1.3.1
By Daniel Diaz
Copyright (C) 1999-2009 Daniel Diaz
https://ideone.com/oN3R1
language:
Prolog (gprolog 1.4.5)
created:
14 years ago
visibility:
public

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