Karate students practicing on a mat.
Students are practicing karate.
Karate students refers to students
exists e1 x1 x2 x3 x4.(a_topic(x1) & on(e1,x4) & n_mat(x4) & Actor(e1,x3) & v_practice(e1) & (x1 = x3) & n_student(x1) & (x1 = x2) & ne_nam_karate(x2))
exists e1 x1 x2.(Theme(e1,x2) & Actor(e1,x1) & v_practice(e1) & n_karate(x2) & n_student(x1))