/* properties and values */

  husband(paul).
  husband(rob).
  husband(stan).
  husband(vern).
  husband(wally).

  day(1).
  day(2).
  day(3).
  day(4).
  day(5).

/* constraints */

  a(anne, 1).
  b(anne, X) :- X \= wally.
  c(stan, 3).
  d(rob, 5).
  e(rob, X) :- X \= ida.
  f(vern, fran).
  g(vern, X, eve, Y) :- X is Y + 1.

/* solve predicate */

solve(Wife1,Husband1,Day1, Wife2,Husband2,Day2, Wife3,Husband3,Day3, Wife4,Husband4,Day4, Wife5,Husband5,Day5) :-

  /* freeze first property */

  Wife1 = anne,
  Wife2 = cathy,
  Wife3 = eve,
  Wife4 = fran,
  Wife5 = ida,

  /* make values of other properties distinct */

  husband(Husband1),
  husband(Husband2),
  husband(Husband3),
  husband(Husband4),
  husband(Husband5),

  Husband1 \= Husband2, Husband1 \= Husband3, Husband1 \= Husband4, Husband1 \= Husband5,
  Husband2 \= Husband3, Husband2 \= Husband4, Husband2 \= Husband5,
  Husband3 \= Husband4, Husband3 \= Husband5,
  Husband4 \= Husband5,

  day(Day1),
  day(Day2),
  day(Day3),
  day(Day4),
  day(Day5),

  Day1 \= Day2, Day1 \= Day3, Day1 \= Day4, Day1 \= Day5,
  Day2 \= Day3, Day2 \= Day4, Day2 \= Day5,
  Day3 \= Day4, Day3 \= Day5,
  Day4 \= Day5,

  /* assert constraints */

  ( a(Wife1, Day1);
    a(Wife2, Day2);
    a(Wife3, Day3);
    a(Wife4, Day4);
    a(Wife5, Day5) ),

  ( b(Wife1, Husband1);
    b(Wife2, Husband2);
    b(Wife3, Husband3);
    b(Wife4, Husband4);
    b(Wife5, Husband5) ),

  ( c(Husband1, Day1);
    c(Husband2, Day2);
    c(Husband3, Day3);
    c(Husband4, Day4);
    c(Husband5, Day5) ),

  ( d(Husband1, Day1);
    d(Husband2, Day2);
    d(Husband3, Day3);
    d(Husband4, Day4);
    d(Husband5, Day5) ),

  ( e(Husband1, Wife1);
    e(Husband2, Wife2);
    e(Husband3, Wife3);
    e(Husband4, Wife4);
    e(Husband5, Wife5) ),

  ( f(Husband1, Wife1);
    f(Husband2, Wife2);
    f(Husband3, Wife3);
    f(Husband4, Wife4);
    f(Husband5, Wife5) ),

  ( g(Husband1, Day1, Wife1, Day1);
    g(Husband1, Day1, Wife2, Day2);
    g(Husband1, Day1, Wife3, Day3);
    g(Husband1, Day1, Wife4, Day4);
    g(Husband1, Day1, Wife5, Day5);
    g(Husband2, Day2, Wife1, Day1);
    g(Husband2, Day2, Wife2, Day2);
    g(Husband2, Day2, Wife3, Day3);
    g(Husband2, Day2, Wife4, Day4);
    g(Husband2, Day2, Wife5, Day5);
    g(Husband3, Day3, Wife1, Day1);
    g(Husband3, Day3, Wife2, Day2);
    g(Husband3, Day3, Wife3, Day3);
    g(Husband3, Day3, Wife4, Day4);
    g(Husband3, Day3, Wife5, Day5);
    g(Husband4, Day4, Wife1, Day1);
    g(Husband4, Day4, Wife2, Day2);
    g(Husband4, Day4, Wife3, Day3);
    g(Husband4, Day4, Wife4, Day4);
    g(Husband4, Day4, Wife5, Day5);
    g(Husband5, Day5, Wife1, Day1);
    g(Husband5, Day5, Wife2, Day2);
    g(Husband5, Day5, Wife3, Day3);
    g(Husband5, Day5, Wife4, Day4);
    g(Husband5, Day5, Wife5, Day5) ).

/* go/0 predicate, prints all solutions */

go :-
  solve(Wife1,Husband1,Day1, Wife2,Husband2,Day2, Wife3,Husband3,Day3, Wife4,Husband4,Day4, Wife5,Husband5,Day5),

  /* print a solution */

  write(Wife1), write('\t'),
  write(Husband1), write('\t'),
  write(Day1), write('\n'),

  write(Wife2), write('\t'),
  write(Husband2), write('\t'),
  write(Day2), write('\n'),

  write(Wife3), write('\t'),
  write(Husband3), write('\t'),
  write(Day3), write('\n'),

  write(Wife4), write('\t'),
  write(Husband4), write('\t'),
  write(Day4), write('\n'),

  write(Wife5), write('\t'),
  write(Husband5), write('\t'),
  write(Day5), write('\n'),

  /* backtrack for all solutions */

  write('\n'), fail.