In the 4-queens problem, ($$x_1$$, $$x_2$$, $$x_3$$, $$x_4$$) co

In the 4-queens problem, ($$x_1$$, $$x_2$$, $$x_3$$, $$x_4$$) correspond to the 4 queens' column indices. During backtracking, (1, 3, 4, ?) will be checked before (1, 4, 2, ?), and none of them has any solution in their branches. ~@[](2)

答案：TRUE