A group of gymnasts performing.
Gymnasts are performing
Gymnast performing is a rephrase of a group of gymnasts are performing.
exists e1 x1 x2 x3.(a_topic(x1) & Actor(e1,x3) & v_perform(e1) & (x1 = x3) & of(x1,x2) & n_gymnast(x2) & n_group(x1))
exists e1 x1.(Actor(e1,x1) & v_perform(e1) & n_gymnast(x1))