People racing on ATV's in full protective garb
The people in ATV's are competitors.
If there's People racing on ATV's you can say people in ATV's are competitors
exists e1 s1 s2 x1 x2 x3 x4 x5.(a_topic(x1) & in(e1,x5) & n_garb(x5) & a_protective(s2) & Theme(s2,x5) & a_full(s1) & Theme(s1,x5) & on(e1,x3) & n_'s(x3) & (x3 = x4) & ne_org_atv(x4) & Actor(e1,x2) & v_race(e1) & (x1 = x2) & n_people(x1))
exists p1 x1 x2 x3.(n_people(x1) & exists x4.((x1 = x4) & n_competitor(x4)) & in(x1,x2) & n_'s(x2) & (x2 = x3) & ne_org_atv(x3))