Three people are in an alley with a dumpster, one skateboarding over the dumpster while the other two look on.
Some of the people are professional skateboarders.
Not all people are professional skateboarders.
exists p1 s1 x1 x2.(-(x2 = x2) & n_look(x2) & card_eq_2(x2) & a_on(s1) & Manner(p1,s1) & while(p1,x2) & exists x3 x4 x5.(in(x1,x3) & with(x3,x4) & rel(x4,x5) & over(x5,x4) & n_dumpster(x4) & n_dumpster(x4) & n_skateboarding(x5) & card_eq_1(x5) & n_alley(x3)) & n_people(x1) & card_eq_3(x1))
exists p1 x1 x2.(n_people(x2) & exists s1 x3.((x1 = x3) & n_skateboarder(x3) & a_professional(s1) & Theme(s1,x3)) & of(x1,x2) & n_thing(x1))