Trucks race in an obstacle course.
Trucks are racing outside.
Not all  trucks racing in an obstacle course is outside.
exists x1 x2 x3 x4.(a_topic(x1) & in(x1,x3) & n_course(x3) & of(x3,x4) & n_obstacle(x4) & n_race(x1) & (x1 = x2) & ne_nam_trucks(x2))
exists e1 p1 x1.(exists s1.(Theme(s1,x1) & a_outside(s1)) & Topic(e1,p1) & Actor(e1,x1) & v_race(e1) & n_truck(x1))