A man is sitting in front of a harpsichord, and a woman is preparing to sing.
woman singing while a man sits by a harpsichord
" Woman singing while a man sits by a harpsichord " is the reversal of Sentence 1.
exists e1 e2 p1 x1 x2 x3 x4.(Topic(e2,p1) & Actor(e2,x4) & v_prepare(e2) & exists e3.(Actor(e3,x4) & v_sing(e3)) & n_woman(x4) & in(e1,x2) & of(x2,x3) & n_harpsichord(x3) & n_front(x2) & Actor(e1,x1) & v_sit(e1) & n_man(x1))
exists e1 p1 x1 x2.(a_topic(x1) & exists e2 x3 x4.(by(e2,x4) & n_harpsichord(x4) & Actor(e2,x3) & v_sit(e2) & n_man(x3)) & while(e1,p1) & Actor(e1,x2) & v_sing(e1) & (x1 = x2) & n_woman(x1))