% Chess board after Alekhnovich04
% unique: u(...) is true if precisely one argument is 1 and the rest are 0
u(1).
u(1,0). u(0,1).
u(1,0,0). u(0,1,0). u(0,0,1).
u(1,0,0,0). u(0,1,0,0). u(0,0,1,0). u(0,0,0,1).
% coding: o=square, x=removed square, number=possible domino
%  o  2 o  6  o    x
%  1    5    10
%  o  4 o  9  o 14 o
%  3    8    13   18
%  o  7 o 12  o 17 o
%      11    16   20
%  x    o 15  o 19 o
test(B):-B=[A1,A2,A3,A4,A5,A6,A7,A8,A9,A10,A11,A12,A13,A14,A15,A16,A17,A18,A19,A20],
     u(A1,A2), 
     u(A1,A4,A3), u(A2,A5,A6),
     u(A3,A7), u(A4,A5,A9,A8), u(A6,A10),
     u(A7,A8,A11,A12), u(A9,A10,A13,A14),
     u(A11,A15), u(A12,A13,A16,A17), u(A14,A18),
     u(A15,A16,A19), u(A17,A18,A20),
     u(A19,A20).
%  o  2 o  6  o 23 x
%  1    5    10   24
%  o  4 o  9  o 14 o
%  3    8    13   18
%  o  7 o 12  o 17 o
% 21   11    16   20
%  x 22 o 15  o 19 o
test2(B):-B=[A1,A2,A3,A4,A5,A6,A7,A8,A9,A10,A11,A12,A13,A14,A15,A16,A17,A18,A19,A20,
A21, A22, A23, A24],
     u(A1,A2), 
     u(A1,A4,A3), u(A2,A5,A6),
     u(A3,A7,A21), u(A4,A5,A9,A8), u(A6,A10,A23),
     u(A21,A22),u(A7,A8,A11,A12), u(A9,A10,A13,A14), u(A23,A24),
     u(A22,A11,A15), u(A12,A13,A16,A17), u(A14,A18,A24),
     u(A15,A16,A19), u(A17,A18,A20),
     u(A19,A20).