People are eating in a restaurant.
Everyone is eating dinner.
People do not have to be eating dinner to be in a restaurant.
exists e1 x1 x2.(in(e1,x2) & n_restaurant(x2) & Actor(e1,x1) & v_eat(e1) & n_people(x1))
all x1.(n_person(x1) -> exists p1 s1 x2.((x1 = x2) & n_dinner(x2) & a_eating(s1) & Theme(s1,x2)))