Four children are playing by an outdoor fountain.
Four children are studying in the library.
The four children cannot be playing outdoors while studying in the library at the same time.
exists e1 s1 x1 x2.(by(e1,x2) & n_fountain(x2) & a_outdoor(s1) & Theme(s1,x2) & Actor(e1,x1) & v_play(e1) & n_child(x1) & card_eq_4(x1))
exists e1 x1 x2.(n_library(x2) & in(e1,x2) & Actor(e1,x1) & v_study(e1) & n_child(x1) & card_eq_4(x1))