People are working on the factory floor while yellow stacks of paper go by.
People are at work indoors
The people are indoors because they are on the factory floor.
exists e1 s1 s2 x1 x2 x3 x4 x5 x6.(n_floor(x2) & of(x2,x3) & n_factory(x3) & a_by(s2) & Manner(e1,s2) & while(e1,x4) & of(x4,x5) & n_go(x5) & of(x5,x6) & n_paper(x6) & n_stack(x4) & a_yellow(s1) & Theme(s1,x4) & on(e1,x2) & Actor(e1,x1) & v_work(e1) & n_people(x1))
exists p1 x1.(exists x2 x3.(at(x1,x2) & n_indoor(x2) & of(x2,x3) & n_work(x3)) & n_people(x1))