A bearded man in a white t-shirt is riding a motorcycle.
Some riders belonging to a rider club are competing in a motorcycle race
A bearded man and some riders are not the same thing.
exists e1 s1 s2 x1 x2 x3.(Theme(e1,x3) & Actor(e1,x1) & v_ride(e1) & n_motorcycle(x3) & in(x1,x2) & n_t-shirt(x2) & a_white(s2) & Theme(s2,x2) & n_man(x1) & a_bearded(s1) & Theme(s1,x1))
exists e1 e2 x1 x2 x3 x4 x5 x6.(in(e2,x5) & n_race(x5) & of(x5,x6) & n_motorcycle(x6) & Actor(e2,x1) & v_compete(e2) & to(e1,x3) & n_club(x3) & of(x3,x4) & n_rider(x4) & Actor(e1,x2) & v_belong(e1) & (x1 = x2) & n_rider(x1))