A man rides his dirt bike.
A person rides around.
A man who rides his dirt bike is a person who rides around.
exists e1 x1 x2 x3.(Theme(e1,x2) & Actor(e1,x1) & v_ride(e1) & n_bike(x2) & of(x2,x3) & n_dirt(x3) & of(x2,x1) & n_male(x1) & n_man(x1))
exists e1 p1 x1.(exists s1.(Theme(s1,x1) & a_around(s1)) & Topic(e1,p1) & Actor(e1,x1) & v_ride(e1) & n_person(x1))