Doctors performing some type of surgery.
Doctors cut open a person.
if doctors are performing surgery, they cut open a person.
exists e1 x1 x2 x3 x4.(a_topic(x1) & Theme(e1,x3) & Actor(e1,x2) & v_perform(e1) & of(x3,x4) & n_surgery(x4) & n_type(x3) & (x1 = x2) & n_doctor(x1))
exists e1 p1 x1.(exists s1 x2.(Theme(s1,x2) & a_open(s1) & n_person(x2)) & Topic(e1,p1) & Actor(e1,x1) & v_cut(e1) & n_doctor(x1))