A gentleman walking in the street.
A gentleman waits on the sidewalk.
Man cannot wait on sidewalk and be walking in street at same time.
exists s1 x1 x2.(n_street(x2) & a_topic(x1) & in(x1,x2) & n_walking(x1) & a_gentleman(s1) & Theme(s1,x1))
exists s1 x1 x2.(n_sidewalk(x2) & a_topic(x1) & on(x1,x2) & n_wait(x1) & a_gentleman(s1) & Theme(s1,x1))