Three men perform with guitars on stage while one sings.
There are 4 men
If three men are playing guitars and one sings, there are 4 men.
exists e1 x1 x2 x3 x4.(while(e1,x4) & n_sing(x4) & card_eq_1(x4) & on(e1,x3) & n_stage(x3) & with(e1,x2) & n_guitar(x2) & Actor(e1,x1) & v_perform(e1) & n_man(x1) & card_eq_3(x1))
exists p1 x1 x2.((x1 = x2) & n_man(x2) & n_date(x2) & a_date_day_04(x2) & a_date_day_04(x2))