A young man wears a helmet and protective clothing as he races his dirt bike through a muddy track.
A tall person with a helmet.
Not all young men are tall.
(-x)
exists s1 x1 x2.(a_topic(x1) & with(x1,x2) & n_helmet(x2) & n_person(x1) & a_tall(s1) & Theme(s1,x1))