A man in glasses sits by himself in a pub.
A guy by himself at the bar.
A man is a guy while a man sits by himself at the pub must be by himself at the bar.
exists e1 x1 x2 x3.(in(e1,x3) & n_pub(x3) & by(e1,x1) & n_male(x1) & Actor(e1,x1) & v_sit(e1) & in(x1,x2) & n_glass(x2) & n_man(x1))
exists x1 x2 x3.(n_bar(x3) & n_male(x2) & a_topic(x1) & at(x1,x3) & by(x1,x2) & n_guy(x1))