1 man singing and 1 man playing a saxophone in a concert.
The 2 men are entertaining some people.
A concert implies people are singing and playing for an audience, so "The 2 men are entertaining some people" is implied.
exists e1 s1 x1 x2 x3 x4 x5 x6.(a_topic(s1) & subset_of(x3,s1) & in(e1,x6) & n_concert(x6) & Theme(e1,x5) & Actor(e1,x4) & v_play(e1) & n_saxophone(x5) & (x3 = x4) & n_man(x3) & n_date(x3) & a_date_day_01(x3) & a_date_day_01(x3) & subset_of(x1,s1) & n_singing(x1) & of(x1,x2) & n_man(x2) & n_date(x1) & a_date_day_01(x1) & a_date_day_01(x1))
exists e1 x1 x2.(n_man(x1) & n_date(x1) & a_date_day_02(x1) & a_date_day_02(x1) & Theme(e1,x2) & Actor(e1,x1) & v_entertain(e1) & n_people(x2))