A person stunt riding on a BMX type of bicycle.
A tall person riding
Not all stunt riders are tall.
exists x1 x2 x3 x4 x5.(a_topic(x1) & on(x1,x3) & of(x3,x5) & n_bicycle(x5) & n_type(x3) & (x3 = x4) & ne_org_bmx(x4) & n_stunt(x1) & Time(x1,x2) & n_riding(x2) & n_person(x1))
exists s1 x1 x2.(a_topic(x1) & Time(x1,x2) & n_riding(x2) & n_person(x1) & a_tall(s1) & Theme(s1,x1))