One man who has a black backpack is approaching an escalator.
A man with drugs in his backpack is approaching the airports escalator.
A man could be carrying something other than drugs in his backpack and the airport has scanners.
exists e1 e2 s1 x1 x2 x3 x4.(Theme(e2,x4) & Actor(e2,x1) & v_approach(e2) & n_escalator(x4) & Theme(e1,x3) & Actor(e1,x2) & v_have(e1) & n_backpack(x3) & a_black(s1) & Theme(s1,x3) & (x1 = x2) & n_man(x1) & card_eq_1(x1))
exists e1 x1 x2 x3 x4 x5.(n_escalator(x4) & of(x4,x5) & n_airport(x5) & Theme(e1,x4) & Actor(e1,x1) & v_approach(e1) & in(x1,x3) & n_backpack(x3) & of(x3,x1) & n_male(x1) & with(x1,x2) & n_drug(x2) & n_man(x1))