array [1..4] of var 1..8: x :: output_array([1..4]);
constraint int_eq(x[1], 8);
constraint int_eq(x[2], 4);
constraint int_eq(x[3], 3);
constraint int_eq(x[4], 1);
constraint int_lt(x[2], x[1]);
constraint int_lt(x[3], x[2]);
constraint int_lt(x[4], x[3]);
solve satisfy;