Two children eating food.
Two children are eating lunch.
The fact that children are eating food does not infer that the food is for any specific mealtime including lunch.
exists e1 x1 x2 x3.(a_topic(x1) & Theme(e1,x3) & Actor(e1,x2) & v_eat(e1) & n_food(x3) & (x1 = x2) & n_child(x1) & card_eq_2(x1))
exists e1 x1 x2.(Theme(e1,x2) & Actor(e1,x1) & v_eat(e1) & n_lunch(x2) & n_child(x1) & card_eq_2(x1))