A man is skateboarding at a park.
A woman is skateboarding at a park.
A man is a male and a woman is a female, they cannot be the same gender.
exists e1 x1 x2.(at(e1,x2) & n_park(x2) & Actor(e1,x1) & v_skateboard(e1) & n_man(x1))
exists e1 x1 x2.(at(e1,x2) & n_park(x2) & Actor(e1,x1) & v_skateboard(e1) & n_woman(x1))