Men wearing hard hats and safety vests are working.
The men are construction workers.
Just because men are wearing hard hats and safety vests does not imply they are construction workers.
exists e2 e1 s1 x1 x2 x3 x4 x5.(Actor(e2,x1) & v_work(e2) & subset_of(x4,x1) & n_vest(x4) & of(x4,x5) & n_safety(x5) & subset_of(x2,x1) & n_hat(x2) & a_hard(s1) & Theme(s1,x2) & Actor(e1,x2) & v_wear(e1) & of(x2,x3) & n_man(x3))
exists p1 x1.(n_man(x1) & exists x2 x3.((x1 = x2) & n_worker(x2) & of(x2,x3) & n_construction(x3)))