Two men are riding on horses through the street.
Two men are riding horses because they're exercising the horses.
Men can ride horses for other reasons than exercising the horses.
exists e1 x1 x2 x3.(n_street(x3) & through(e1,x3) & on(e1,x2) & n_horse(x2) & Actor(e1,x1) & v_ride(e1) & n_man(x1) & card_eq_2(x1))
exists e1 p1 x1 x2.(exists e2.(Theme(e2,x2) & Actor(e2,x1) & v_exercise(e2)) & n_horse(x2) & n_horse(x2) & n_thing(x1) & because(e1,p1) & Theme(e1,x2) & Actor(e1,x1) & v_ride(e1) & n_man(x1) & card_eq_2(x1))