Three friends have fun bicycling.
Three friends are enjoying the day.
We don't know that it is day time or night time, so we don't know if the friends are enjoying the day.  Just because they have fun bicycling doesn't mean that the rest of the day is enjoyable.
exists e1 x1 x2 x3.(Theme(e1,x2) & Actor(e1,x1) & v_have(e1) & n_bicycling(x2) & of(x2,x3) & n_fun(x3) & n_friend(x1) & card_eq_3(x1))
exists e1 x1 x2.(n_day(x2) & Theme(e1,x2) & Actor(e1,x1) & v_enjoy(e1) & n_friend(x1) & card_eq_3(x1))