A man and a child sitting in a blue net.
A father son trapeze team sitting on the safety net.
You  can not infer there is a safety net.
exists e1 s1 s2 x1 x2 x3 x4.(a_topic(s1) & subset_of(x2,s1) & in(e1,x4) & n_net(x4) & a_blue(s2) & Theme(s2,x4) & Actor(e1,x3) & v_sit(e1) & (x2 = x3) & n_child(x2) & subset_of(x1,s1) & n_man(x1))
exists e1 x1 x2 x3 x4 x5 x6.(n_net(x5) & of(x5,x6) & n_safety(x6) & for(e1,x1) & on(e1,x5) & Actor(e1,x3) & v_sit(e1) & n_team(x3) & of(x3,x4) & n_trapeze(x4) & n_son(x1) & of(x1,x2) & n_father(x2))