A person riding a skateboard.
A man catches a frisbee with his left hand.
riding skateboard and catching Frisbee - contradictory
exists e1 x1 x2 x3.(a_topic(x1) & Theme(e1,x3) & Actor(e1,x2) & v_ride(e1) & n_skateboard(x3) & (x1 = x2) & n_person(x1))
exists e1 s1 x1 x2 x3.(Theme(e1,x2) & Actor(e1,x1) & v_catch(e1) & with(x2,x3) & n_hand(x3) & a_left(s1) & Theme(s1,x3) & of(x3,x1) & n_male(x1) & n_frisbee(x2) & n_man(x1))