I learned it from the book 'Seven languages in seven weeks', it is so fun solving Sudoku using Prolog! 一种用来快速解决Sudoku的编程方式--逻辑编程，Programming Logically！ 如果用来解决6＊6或者9＊9的Sudoku，更改构造的Puzzle即可。

sudoku.pro

/*验证该列表中没有重复的数字*/
valid([]).
valid([Head|Tail]) :-
   fd_all_different(Head),
   valid(Tail).

/*构造Puzzle*/
sudoku(Puzzle, Solution) :-
   Solution = Puzzle,
   Puzzle = [S11, S12, S13, S14,
             S21, S22, S23, S24,
             S31, S32, S33, S34,
             S41, S42, S43, S44],
   fd_domain(Puzzle, 1, 4),
   
   Row1 = [S11, S12, S13, S14],
   Row2 = [S21, S22, S23, S24],
   Row3 = [S31, S32, S33, S34],
   Row4 = [S41, S42, S43, S44],

   Col1 = [S11, S21, S31, S41],
   Col2 = [S12, S22, S32, S42],
   Col3 = [S13, S23, S33, S43],
   Col4 = [S14, S24, S34, S44],

   Square1 = [S11, S12, S21, S22],
   Square2 = [S13, S14, S23, S24],
   Square3 = [S31, S32, S41, S42],
   Square4 = [S33, S34, S43, S44],

   valid([Row1, Row2, Row3, Row4,
         Col1, Col2, Col3, Col4,
         Square1, Square2, Square3, Square4]).