A gentleman walking in the street.
A man is sitting at his desk.
Man cannot be sitting at desk and walking in street simultaneously.
exists s1 x1 x2.(n_street(x2) & a_topic(x1) & in(x1,x2) & n_walking(x1) & a_gentleman(s1) & Theme(s1,x1))
exists e1 x1 x2.(at(e1,x2) & n_desk(x2) & of(x2,x1) & n_male(x1) & Actor(e1,x1) & v_sit(e1) & n_man(x1))