A skinny guy is eating a sandwich while using the computer.
The guy needs to gain weight
Not everyone that eats sandwich does so necessarily to gain weight.
exists e2 e1 s1 x1 x2 x3.(n_computer(x3) & while(e1,e2) & Theme(e2,x3) & Actor(e2,x1) & v_use(e2) & Theme(e1,x2) & Actor(e1,x1) & v_eat(e1) & n_sandwich(x2) & n_guy(x1) & a_skinny(s1) & Theme(s1,x1))
exists e1 p1 x1.(n_guy(x1) & Topic(e1,p1) & Actor(e1,x1) & v_need(e1) & exists e2 x2.(Theme(e2,x2) & Actor(e2,x1) & v_gain(e2) & n_weight(x2)))