A man in a brown jacket stands on a bus.
Everyone is sitting.
A man cannot be standing on a bus if everyone is sitting.
exists e1 s1 x1 x2 x3.(on(e1,x3) & n_bus(x3) & Actor(e1,x1) & v_stand(e1) & in(x1,x2) & n_jacket(x2) & a_brown(s1) & Theme(s1,x2) & n_man(x1))
all x1.(n_person(x1) -> exists e1.(Actor(e1,x1) & v_sit(e1)))