Three boys in life jackets float on a raft.
The boys are in the library reading books.
One cannot be in the library reading books and on a raft at the same time.
exists e1 x1 x2 x3 x4.(on(e1,x4) & n_raft(x4) & Actor(e1,x1) & v_float(e1) & in(x1,x2) & n_jacket(x2) & of(x2,x3) & n_life(x3) & n_boy(x1) & card_eq_3(x1))
exists p1 x1 x2 x3 x4.(n_book(x2) & of(x2,x4) & n_reading(x4) & of(x2,x3) & n_library(x3) & n_boy(x1) & in(x1,x2))