Person sitting at a desk in a library.
The person is in a library.
The person is sitting at a desk because they are at the library.
exists e1 x1 x2 x3.(ne_nam_person(x1) & in(e1,x3) & n_library(x3) & at(e1,x2) & n_desk(x2) & Actor(e1,x1) & v_sit(e1))
exists p1 x1.(n_person(x1) & exists x2.(in(x1,x2) & n_library(x2)))