Men in orange vests and white hard hats stand on scaffolds working.
Men stand on the scaffolds while working on concrete.
Just because men are working it does not meaning they are working on concrete.
exists e2 e1 s1 s2 x1 x2 x3 x4 x5 x6.(for(e1,e2) & Actor(e2,x1) & v_work(e2) & on(e1,x6) & n_scaffold(x6) & Actor(e1,x1) & v_stand(e1) & in(x1,x2) & n_hat(x5) & a_hard(s2) & Theme(s2,x5) & a_white(s1) & Theme(s1,x5) & n_vest(x4) & subset_of(x5,x2) & subset_of(x4,x2) & of(x2,x3) & n_orange(x3) & n_man(x1))
exists e2 e1 x1 x2 x3.(n_scaffold(x2) & while(e1,e2) & on(e2,x3) & n_concrete(x3) & Actor(e2,x1) & v_work(e2) & on(e1,x2) & Actor(e1,x1) & v_stand(e1) & n_man(x1))