A boy is skateboarding at night.
The boy is cycling in the morning.
Morning is the opposite of night. Skateboarding and cycling are not the same thing.
exists e1 x1 x2.(at(e1,x2) & n_night(x2) & Actor(e1,x1) & v_skateboard(e1) & n_boy(x1))
exists e1 x1 x2.(n_morning(x2) & n_boy(x1) & in(e1,x2) & Actor(e1,x1) & v_cycle(e1))