The boy in swim trunks is laying face down on a watery pavement.
The boy is waiting for his friends.
There is no evidence the boy in swim trucks is laying face down on a watery pavement while he is waiting for his friends. You can not assume this boy even has any friends much less is waiting for them.
exists e1 x1 x2 x3 x4 x5 x6.(n_boy(x1) & on(e1,x5) & n_pavement(x5) & of(x5,x6) & n_watery(x6) & r_down(e1) & Theme(e1,x4) & Actor(e1,x1) & v_lay(e1) & n_face(x4) & in(x1,x2) & n_trunk(x2) & of(x2,x3) & n_swim(x3))
exists e1 x1 x2.(n_friend(x2) & of(x2,x1) & n_male(x1) & n_boy(x1) & for(e1,x2) & Actor(e1,x1) & v_wait(e1))