A man and a boy are preparing food to be cooked on the fire.
A man and a boy are about to cook food on a fire while camping.
Answer :The fact that a man and a boy are  preparing food does not mean they are camping
exists e1 p1 x1 x2 x3 x4 x5.(n_fire(x5) & on(e1,x5) & Theme(e1,x4) & Actor(e1,x1) & v_prepare(e1) & Topic(x4,p1) & exists e2.(Theme(e2,x4) & v_cook(e2)) & n_food(x4) & subset_of(x3,x1) & n_boy(x3) & subset_of(x2,x1) & n_man(x2))
exists p1 s1 x1 x2 x3.(Topic(s1,p1) & Actor(s1,x1) & a_about(s1) & exists e2 e1 x4 x5.(while(e1,e2) & Actor(e2,x1) & v_camp(e2) & on(e1,x5) & n_fire(x5) & Theme(e1,x4) & Actor(e1,x1) & v_cook(e1) & n_food(x4)) & subset_of(x3,x1) & n_boy(x3) & subset_of(x2,x1) & n_man(x2))