Two surgeons performing a surgery.
Two doctors doing a heart transplant
The surgeons may be doing a different procedure, not a heart transplant.
exists e1 x1 x2 x3.(a_topic(x1) & Theme(e1,x3) & Actor(e1,x2) & v_perform(e1) & n_surgery(x3) & (x1 = x2) & n_surgeon(x1) & card_eq_2(x1))
exists e1 x1 x2 x3 x4.(a_topic(x1) & Theme(e1,x3) & Actor(e1,x2) & v_do(e1) & n_transplant(x3) & of(x3,x4) & n_heart(x4) & (x1 = x2) & n_doctor(x1) & card_eq_2(x1))