Three girls in a classroom with blue and brown desks.
There are desks in the classroom.
Inside the classroom there are desk, the colors of the desk are blue and brown. Sentence one, just elaborates more on the descripton of the desk.
exists s1 s2 x1 x2 x3.(a_topic(x1) & in(x1,x2) & with(x2,x3) & n_desk(x3) & a_brown(s2) & Theme(s2,x3) & a_blue(s1) & Theme(s1,x3) & n_classroom(x2) & n_girl(x1) & card_eq_3(x1))
exists p1 x1 x2.(n_classroom(x2) & in(p1,x2) & exists x3.((x1 = x3) & n_desk(x3)))