A man with long hair is playing a guitar.
A hippie plays a cover of a Led Zeppelin song at a concert.
A man with long hair doesn't necessarily mean a hippie. The fact that a man with long hair is playing a guitar doesn't imply that he plays a cover of Led Zeppelin song at a concert.
exists e1 s1 x1 x2 x3.(Theme(e1,x3) & Actor(e1,x1) & v_play(e1) & n_guitar(x3) & with(x1,x2) & n_hair(x2) & a_long(s1) & Theme(s1,x2) & n_man(x1))
exists e1 e2 x1 x2 x3 x4 x5.(Theme(e2,x2) & Actor(e2,x1) & v_play(e2) & of(x2,x3) & at(x3,x5) & n_concert(x5) & n_song(x3) & (x3 = x4) & ne_nam_zeppelin(x4) & Theme(e1,x3) & v_lead(e1) & n_cover(x2) & n_hippie(x1))