two men work on a piece of machinery.
Two men are stumped by the new machinery.
Sentence 1 is missing  men are stumped
exists e1 x1 x2 x3.(on(e1,x2) & of(x2,x3) & n_machinery(x3) & n_piece(x2) & Actor(e1,x1) & v_work(e1) & n_man(x1) & card_eq_2(x1))
exists e1 s1 x1 x2.(n_machinery(x2) & a_new(s1) & Theme(s1,x2) & Actor(e1,x2) & Theme(e1,x1) & v_stump(e1) & n_man(x1) & card_eq_2(x1))