Three kids are playing musical instrument in a music concert.
Kids a performing for their parents.
The fact that the three kids are playing musical instruments in a music concert doesn't necessarily imply they are performing for their parents.
exists e1 s1 x1 x2 x3 x4.(in(e1,x3) & n_concert(x3) & of(x3,x4) & n_music(x4) & Theme(e1,x2) & Actor(e1,x1) & v_play(e1) & n_instrument(x2) & a_musical(s1) & Theme(s1,x2) & n_kid(x1) & card_eq_3(x1))
all x3 x1.((n_parent(x3) & of(x3,x1) & n_thing(x1) & n_perform(x1)) -> exists x2.(a_topic(x2) & for(x2,x3) & for(x2,x1) & n_kid(x2)))