A mounted policeman in yellow is patrolling the streets.
The cop is the sheriff of the town.
We don't know from the first sentence that the policeman is a sheriff.
exists e1 s1 x1 x2 x3.(n_street(x3) & Theme(e1,x3) & Actor(e1,x1) & v_patrol(e1) & in(x1,x2) & n_yellow(x2) & n_policeman(x1) & a_mount(s1) & Theme(s1,x1))
exists p1 x1 x2 x3.(n_town(x3) & n_sheriff(x2) & n_cop(x1) & (x1 = x2) & of(x2,x3))