The room is carpeted.
There is tile on the floor
Carpet and tile are different floor covering materials.
exists e1 x1.(n_room(x1) & Theme(e1,x1) & v_carpet(e1))
exists p1 x1 x3.(n_floor(x3) & exists x2.((x1 = x2) & on(x2,x3) & n_tile(x2)))