A bearded man is playing a banjo.
A bearded man plays a banjo while his son watches.
A bearded man can play a banjo even if his son doesn't watch him.
exists e1 s1 x1 x2.(Theme(e1,x2) & Actor(e1,x1) & v_play(e1) & n_banjo(x2) & n_man(x1) & a_bearded(s1) & Theme(s1,x1))
exists e1 s1 x1 x2 x3 x4.(Time(e1,x4) & n_watch(x4) & while(e1,x3) & n_son(x3) & of(x3,x1) & n_male(x1) & Theme(e1,x2) & Actor(e1,x1) & v_play(e1) & n_banjo(x2) & n_man(x1) & a_bearded(s1) & Theme(s1,x1))