A group of children are playing on swings.
There is a group of workers building a playground.
Children playing and workers building is different activities
exists e1 x1 x2 x3.(on(e1,x3) & n_swing(x3) & Actor(e1,x1) & v_play(e1) & of(x1,x2) & n_child(x2) & n_group(x1))
exists p1 x1 e1 x2 x3 x4 x5.((x1 = x2) & Theme(e1,x5) & Actor(e1,x4) & v_build(e1) & n_playground(x5) & (x2 = x4) & of(x2,x3) & n_worker(x3) & n_group(x2))