The floor is tiled.
The floor has a checker pattern
Not all tile floors have to have a checker pattern.
exists e1 x1.(n_floor(x1) & Theme(e1,x1) & v_tile(e1))
exists e1 x1 x2 x3.(n_floor(x1) & Theme(e1,x2) & Actor(e1,x1) & v_have(e1) & n_pattern(x2) & of(x2,x3) & n_checker(x3))