There is a man and a lady sitting on a bench in front of a stone building and there is another bench next to that one with a lady sitting alone on it.
A man and woman are sitting on a bench next to a lady sitting alone on another bench.
"man and woman are sitting on a bench next to a lady sitting alone on another bench" is just another way to state the information given in the first sentence
exists e1 p1 p2 x1 x2 x3 x4 x5 x6 x7 x8 x9 x13.(n_one(x13) & exists e2 p3 x11 x12 x14 x15.((x2 = x11) & to(x12,x13) & with(x13,x14) & on(e2,x3) & exists s1.(Theme(s1,x15) & a_alone(s1)) & Topic(e2,p3) & Actor(e2,x15) & v_sit(e2) & (x14 = x15) & n_lady(x14) & next(x11,x12) & n_thing(x12) & n_bench(x11) & -(x11 = x5)) & n_thing(x3) & n_bench(x5) & n_bench(x5) & subset_of(x9,x2) & subset_of(x3,x2) & in(e1,x6) & of(x6,x7) & n_building(x7) & of(x7,x8) & n_stone(x8) & n_front(x6) & on(e1,x5) & Actor(e1,x4) & v_sit(e1) & (x3 = x4) & n_lady(x3) & exists x10.((x1 = x10) & n_man(x10)))
exists e2 e1 p1 x1 x2 x3 x4 x5 x6 x7.(to(e1,x5) & on(e2,x7) & n_bench(x7) & -(x7 = x4) & n_bench(x4) & n_bench(x4) & exists s1.(Theme(s1,x6) & a_alone(s1)) & Topic(e2,p1) & Actor(e2,x6) & v_sit(e2) & (x5 = x6) & n_lady(x5) & r_next(e1) & on(e1,x4) & Actor(e1,x1) & v_sit(e1) & n_woman(x3) & n_man(x2) & subset_of(x3,x1) & subset_of(x2,x1))