A group of men wearing hard hats and orange reflector vests are commemorating an event.
Construction workers are commemorating an event.
It does not say in the first sentence that they are construction workers.
exists e1 e2 s1 x1 x2 x3 x4 x5 x6 x7 x8 x9.(Theme(e2,x9) & Actor(e2,x1) & v_commemorate(e2) & n_event(x9) & of(x1,x2) & Theme(e1,x4) & Actor(e1,x3) & v_wear(e1) & subset_of(x6,x4) & n_vest(x6) & of(x6,x8) & n_reflector(x8) & of(x6,x7) & n_orange(x7) & subset_of(x5,x4) & n_hat(x5) & a_hard(s1) & Theme(s1,x5) & (x2 = x3) & n_man(x2) & n_group(x1))
exists e1 x1 x2 x3.(Theme(e1,x3) & Actor(e1,x1) & v_commemorate(e1) & n_event(x3) & n_worker(x1) & of(x1,x2) & n_construction(x2))