A man plays a keyboard and sings.
A singer rehearses a song with his keyboard.
A man that plays a keyboard and sings doesn't always rehearses songs.
exists e1 x1 x2 x3 x4.(Theme(e1,x2) & Actor(e1,x1) & v_play(e1) & n_sing(x4) & n_keyboard(x3) & subset_of(x4,x2) & subset_of(x3,x2) & n_man(x1))
exists e1 x1 x2 x3.(Theme(e1,x2) & Actor(e1,x1) & v_rehearse(e1) & with(x2,x3) & n_keyboard(x3) & of(x3,x1) & n_male(x1) & n_song(x2) & n_singer(x1))