A man in a swimming pool holds a smiling boy in a flotation device.
A man tries to prevent a boy from drowning.
The man is not necessarily trying to prevent the boy from drowning. The pool may not even be deep enough for the boy to drown in.
exists e1 e2 x1 x2 x3 x4 x5 x6.(Theme(e2,x4) & Actor(e2,x1) & v_hold(e2) & in(x4,x5) & n_device(x5) & of(x5,x6) & n_flotation(x6) & n_boy(x4) & Actor(e1,x4) & v_smile(e1) & in(x1,x2) & n_pool(x2) & of(x2,x3) & n_swimming(x3) & n_man(x1))
exists e1 p1 x1.(Topic(e1,p1) & Actor(e1,x1) & v_try(e1) & exists e2 e3 x2 x3.(from(e2,e3) & Actor(e3,x3) & v_drown(e3) & Theme(e2,x2) & Actor(e2,x1) & v_prevent(e2) & n_boy(x2)) & n_man(x1))