A baby in a highchair.
A baby is eating lunch.
Sentence 1 is missing eating lunch
exists x1 x2.(a_topic(x1) & in(x1,x2) & n_highchair(x2) & n_baby(x1))
exists e1 x1 x2.(Theme(e1,x2) & Actor(e1,x1) & v_eat(e1) & n_lunch(x2) & n_baby(x1))